Android学习笔记总结

第一步：

Android(1) - 在 Windows 下搭建 Android 开发环境，以及 Hello World 程序

搭建 Android 的开发环境，以及写一个简单的示例程序

· 在 Windows 下搭建 Android 开发环境

· Android 项目的目录结构说明

· 写一个简单的 Hello World 程序

一、在 Windows 下搭建 Android 开发环境 1、安装 JDK (Java Development Kit) http://download.java.net/jdk6/ 2、安装 Android SDK http://developer.android.com/sdk 3、安装 Eclipse http://www.eclipse.org/ 4、打开 Eclipse ，并安装其 Android 插件（ADT）打开菜单 "Help" -> "Install New Software"，在 "Availabe Software" 中加入地址 http://dl-ssl.google.com/android/eclipse/ ，然后安装 ADT(Android Development Tools) 5、新建 Android 项目 "New" -> Android Project，Project Name - 项目名称；Build Target - 编译项目的 SDK 版本；Application name - 程序名称；Package name - 包名；Min SDK Version - 程序所支持的最低 SDK 版本代号（2 对应 1.1，3 对应 1.5，4 对应 1.6） 6、运行 Android 项目打开菜单 "Run" -> "Run Configurations" -> New launch configuration，设置启动项目名称，在 Android 选项卡中选择启动项目，在 Target 选项卡中设置模拟器 7、创建/使用模拟 SD 卡创建 SD 卡，运行类似如下命令：mksdcard -l sdcard 512M d:\android\sdcard.img 模拟器中使用 SD 卡，在项目配置的 Target 选项卡的 "Additional Emulator Command Line Options" 框中输入类似如下参数：-sdcard d:\android\sdcard.img 8、配置模拟器运行类似如下命令：android create avd --name android15 --target 2。或者直接在菜单 "Window" -> "Android AVD Manager" 中配置模拟器 9、浏览模拟 SD 卡中的内容调试程序，在 DDMS 中选择 "File Explorer" ，在其中的 sdcard 目录下就是模拟 SD 卡中的内容 10、查看日志 LogCat Window -> Show View -> Other -> Android -> LogCat 11、在模拟器中安装/卸载 apk 安装 apk 运行类似如下命令：adb install name.apk；卸载 apk 运行类似如下命令：adb uninstall packagename（注：这里的参数是需要卸载的包名） 12、反编译 Android 程序解压 apk 文件，取出其中的 classes.dex 文件，运行类似如下命令：dexdump.exe -d classes.dex > dump.txt（其意思是将 classes.dex dump 出来，并将反编译后的代码保存到指定的文本文件中） 13、人品不好是出现的某些错误的解决办法如果出现类似如下的错误等 no classfiles specified Conversion to Dalvik format failed with error 1 解决办法：Project -> Clean 出现 Android SDK Content Loader 60% （一直卡在 60%）解决办法：Project -> 去掉 Build Automatically 前面的勾 14、查看 SDK 源代码先想办法搞到源代码，如这个地址 http://www.digginmobile.com/android.asp ，然后将其解压到 SDK 根路径下的 sources 文件夹内即可二、Android 项目的目录结构 1、src - 用于放置源程序 2、gen - 自动生成 R.java 文件，用于引用资源文件（即 res 目录下的数据） 3、assets - 用于放置原始文件，Android 不会对此目录下的文件做任何处理，这是其与 res 目录不同的地方 4、res/drawable - 用于放置图片之类的资源；res/layout - 用于放置布局用的 xml 文件；res/values - 用于放置一些常量数据 5、AndroidManifest.xml - Android 程序的清单文件，相当于配置文件，配置应用程序名称、图标、Activity、Service、Receiver等三、Hello World 程序 1、res/layout/main.xml

代码

<?xml version="1.0" encoding="utf-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:id="@+id/layout" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/txt" /> </LinearLayout>

2、res/values/strings.xml

代码

<?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">layout 直接调用 values 中的字符串</string> <string name="hello2">编程方式调用 values 中的字符串</string> <string name="app_name">webabcd_hello</string> </resources>

3、res/drawable 目录下放置一个名为 icon.png 的图片文件 4、AndroidManifest.xml

代码

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.webabcd.hello" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".Main" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> <uses-sdk android:minSdkVersion="3" /> </manifest>

5、Main.java

代码

package com.webabcd.hello; import android.app.Activity; import android.os.Bundle; import android.widget.LinearLayout; import android.widget.TextView; public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // 将指定的布局文件作为 Activity 所显示的内容 setContentView(R.layout.main); // 动态地在指定的容器控件上添加新的控件 TextView txt = new TextView(this); txt.setText("动态添加控件"); // setContentView(txt); ((LinearLayout)this.findViewById(R.id.layout)).addView(txt); // 引用资源文件内的内容作为输出内容 TextView txt1 = (TextView)this.findViewById(R.id.txt); txt1.setText(this.getString(R.string.hello2)); } }

Android(2) - 布局(Layout)和菜单(Menu)

介绍在 Android 中各种布局的应用，以及菜单效果的实现

· 各种布局方式的应用，FrameLayout, LinearLayout, TableLayout, AbsoluteLayout, RelativeLayout

· 为指定元素配置上下文菜单，为应用程序配置选项菜单，以及多级菜单的实现

1、各种布局方式的演示 res/layout/main.xml

Android学习笔记总结代码

列1"列2"列3"列1" /> </TableRow> </TableLayout>  <AbsoluteLayout android:layout_height="wrap_content" android:layout_width="fill_parent"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="AbsoluteLayout" android:layout_x="100px" android:layout_y="100px" /> </AbsoluteLayout>  <RelativeLayout android:id="@+id/RelativeLayout01" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="wrap_content" android:id="@+id/abc" android:layout_height="wrap_content" android:text="centerInParent=true" android:layout_centerInParent="true" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="marginLeft=20px" android:layout_marginLeft="20px" /> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="xxx" android:layout_below="@id/abc" android:layout_alignRight="@id/abc" /> </RelativeLayout> </LinearLayout>

res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">Hello Layout</string> <string name="app_name">webabcd_layout</string> </resources>

Main.java

Android学习笔记总结代码

package com.webabcd.layout; import android.app.Activity; import android.os.Bundle; public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); } }

2、上下文菜单，选项菜单，子菜单 res/layout/main.xml

Android学习笔记总结代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/txt1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello_contextMenu" /> <TextView android:id="@+id/txt2" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello_subMenu" /> </LinearLayout>

res/values/strings.xml

Android学习笔记总结代码

<?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello_contextMenu">Hello Context Menu</string> <string name="hello_subMenu">Hello Context Sub Menu</string> <string name="app_name">webabcd_menu</string> </resources>

Main.java

Android学习笔记总结代码

package com.webabcd.menu; import android.app.Activity; import android.os.Bundle; import android.view.ContextMenu; import android.view.Menu; import android.view.MenuItem; import android.view.SubMenu; import android.view.View; import android.view.ContextMenu.ContextMenuInfo; import android.widget.TextView; import android.widget.Toast; // 演示两种菜单的实现方式：上下文菜单（通过在某元素上长按，来呼出菜单）和选项菜单（通过按手机上的菜单按钮，来呼出菜单） public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // 为 R.id.txt1 注册一个上下文菜单（在此 TextView 上长按，则会呼出上下文菜单） // 具体呼出的菜单内容需要重写 onCreateContextMenu 来创建 TextView txt1 = (TextView) this.findViewById(R.id.txt1); this.registerForContextMenu(txt1); // 为 R.id.txt2 注册一个上下文菜单 TextView txt2 = (TextView) this.findViewById(R.id.txt2); this.registerForContextMenu(txt2); } // 重写 onCreateContextMenu 用以创建上下文菜单 // 重写 onContextItemSelected 用以响应上下文菜单 @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { super.onCreateContextMenu(menu, v, menuInfo); // 创建 R.id.txt1 的上下文菜单 if (v == (TextView) this.findViewById(R.id.txt1)) { // ContextMenu.setIcon() - 设置菜单的图标 // ContextMenu.setHeaderTitle() - 设置菜单的标题 menu.setHeaderIcon(R.drawable.icon01); menu.setHeaderTitle("我是菜单"); // 用 ContextMenu.add() 来增加菜单项，返回值为 MenuItem // 第一个参数：组ID // 第二个参数：菜单项ID // 第三个参数：顺序号 // 第四个参数：菜单项上显示的内容 menu.add(1, 0, 0, "菜单1"); // MenuItem - 新增菜单项后的返回类型，针对菜单项的其他设置在此对象上操作 menu.add(1, 1, 1, "菜单2").setCheckable(true); } // 创建 R.id.txt2 的上下文菜单（多级上下文菜单） else if (v == (TextView) this.findViewById(R.id.txt2)) { // ContextMenu.addSubMenu("菜单名称") - 用来添加子菜单。子菜单其实就是一个特殊的菜单 SubMenu sub = menu.addSubMenu("父菜单1"); sub.setIcon(R.drawable.icon01); sub.add(0, 0, 0, "菜单1"); sub.add(0, 1, 1, "菜单2"); sub.setGroupCheckable(1, true, true); SubMenu sub2 = menu.addSubMenu("父菜单2"); sub2.setIcon(R.drawable.icon01); sub2.add(1, 0, 0, "菜单3"); sub2.add(1, 1, 1, "菜单4"); sub2.setGroupCheckable(1, true, false); } } // 重写 onCreateOptionsMenu 用以创建选项菜单 @Override public boolean onCreateOptionsMenu(Menu menu) { MenuItem menuItem = menu.add(0, 0, 0, "菜单111111111111111111111"); // MenuItem.setIcon() - 设置菜单项的图标 // MenuItem.setTitleCondensed() - 菜单的简标题，如果指定了简标题的话，菜单项上的标题将会以此简标题为准 // MenuItem.setAlphabeticShortcut() - 设置选中此菜单项的快捷键 // 注：菜单项超过 6 个的话，第 6 个菜单将会变为 More 菜单，多余的菜单会在单击 More 菜单之后显示出来 menuItem.setIcon(R.drawable.icon01); menuItem.setTitleCondensed("菜单1"); menuItem.setAlphabeticShortcut('a'); menu.add(0, 1, 1, "菜单2").setIcon(R.drawable.icon02); menu.add(0, 2, 2, "菜单3").setIcon(R.drawable.icon03); menu.add(0, 3, 3, "菜单4"); menu.add(0, 4, 4, "菜单5"); menu.add(0, 5, 5, "菜单6"); menu.add(0, 6, 6, "菜单7").setIcon(R.drawable.icon04); menu.add(0, 7, 7, "菜单8").setIcon(R.drawable.icon05); return true; } // 重写 onOptionsItemSelected 用以响应选项菜单 @Override public boolean onOptionsItemSelected(MenuItem item) { super.onOptionsItemSelected(item); Toast.makeText(Main.this, "被单击的菜单项为：" + String.valueOf(item.getItemId()), Toast.LENGTH_SHORT).show(); return false; } }

Android(3) - 对话框(Dialog)和通知(Notification)

介绍在 Android 中种对话框及各种通知效果的应用

· 常用对话框的使用，弹出式对话框、日期选择对话框、时间选择对话框、进度条对话框

· 通知（出现在通知列表）和提示性通知（Toast）的演示

1、常用对话框的演示 res/layout/main.xml

Android学习笔记总结代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/txtMsg" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView> <Button android:id="@+id/btn1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn2" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn3" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn4" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn5" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn6" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> </LinearLayout>

res/layout/view.xml

Android学习笔记总结代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:text="我是一个 View" android:layout_width="wrap_content" android:layout_height="wrap_content"> </TextView> </LinearLayout>

res/values/array.xml

<?xml version="1.0" encoding="utf-8"?> <resources>  <string-array name="ary"> <item>项目 1</item> <item>项目 2</item> </string-array> </resources>

Main.java

Android学习笔记总结代码

package com.webabcd.dialog; import java.util.Calendar; import android.app.Activity; import android.app.AlertDialog; import android.app.DatePickerDialog; import android.app.Dialog; import android.app.ProgressDialog; import android.app.TimePickerDialog; import android.app.DatePickerDialog.OnDateSetListener; import android.app.TimePickerDialog.OnTimeSetListener; import android.content.DialogInterface; import android.content.DialogInterface.OnClickListener; import android.os.Bundle; import android.view.View; import android.widget.DatePicker; import android.widget.TextView; import android.widget.TimePicker; import android.widget.Button; public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // 弹出式对话框的 Demo。先调用 Builder()，在 Create()，需要显示对话框的是后再调用 show() AlertDialog dialog = new AlertDialog.Builder(this).setTitle("弹出对话框").create(); dialog.show(); // 以下是各种对话框的 Demo MyButtonClickListener listener = new MyButtonClickListener(); Button btn1 = (Button) this.findViewById(R.id.btn1); btn1.setText("简单的对话框的 Demo"); btn1.setOnClickListener(listener); Button btn2 = (Button) this.findViewById(R.id.btn2); btn2.setText("包括常用设置的对话框(数据来自 xml)"); btn2.setOnClickListener(listener); Button btn3 = (Button) this.findViewById(R.id.btn3); btn3.setText("弹出的对话框的内容是一个 View"); btn3.setOnClickListener(listener); Button btn4 = (Button) this.findViewById(R.id.btn4); btn4.setText("日期选择对话框"); btn4.setOnClickListener(listener); Button btn5 = (Button) this.findViewById(R.id.btn5); btn5.setText("时间选择对话框"); btn5.setOnClickListener(listener); Button btn6 = (Button) this.findViewById(R.id.btn6); btn6.setText("进度条对话框"); btn6.setOnClickListener(listener); } class MyButtonClickListener implements View.OnClickListener { @Override public void onClick(View v) { // 具体的对话框的实现可以通过重写 onCreateDialog 完成 switch (v.getId()) { case R.id.btn1: Main.this.showDialog(0); break; case R.id.btn2: Main.this.showDialog(1); break; case R.id.btn3: Main.this.showDialog(2); break; case R.id.btn4: Main.this.showDialog(3); break; case R.id.btn5: Main.this.showDialog(4); break; case R.id.btn6: Main.this.showDialog(5); break; } } } @Override public Dialog onCreateDialog(int id) { switch (id) { case 0: // 一个简单的弹出对话框 return new AlertDialog.Builder(this).setTitle("这是一个简单的弹出对话框的 Demo") .create(); case 1: // 一个相对复杂的弹出对话框 return new AlertDialog.Builder(this) .setTitle("标题") // 设置标题 // .setCustomTitle(View) // 以一个 View 作为标题 .setIcon(R.drawable.icon01) // 设置标题图片 // .setMessage("信息") // 需要显示的弹出内容 .setPositiveButton("确定", new OnClickListener() { // 设置弹框的确认按钮所显示的文本，以及单击按钮后的响应行为 @Override public void onClick(DialogInterface a0, int a1) { TextView txtMsg = (TextView) Main.this.findViewById(R.id.txtMsg); txtMsg.append("单击了对话框上的“确认”按钮\n"); } }) .setItems(R.array.ary, new DialogInterface.OnClickListener() { // 弹框所显示的内容来自一个数组。数组中的数据会一行一行地依次排列 public void onClick(DialogInterface dialog, int which) { } }) // 其他常用方法如下 // .setMultiChoiceItems(arg0, arg1, arg2) // .setSingleChoiceItems(arg0, arg1, arg2) // .setNeutralButton(arg0, arg1) // .setNegativeButton(arg0, arg1) .create(); case 2: // 弹出对话框为指定的 View 的 Demo return new AlertDialog.Builder(this).setTitle("此对话框的内容是一个 View") .setView(this.findViewById(R.layout.view)).create(); case 3: // 弹出日期选择对话框 Calendar c = Calendar.getInstance(); return new DatePickerDialog(this, new OnDateSetListener() { @Override public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) { TextView txtMsg = (TextView) Main.this.findViewById(R.id.txtMsg); txtMsg.append("新设置的日期为：" + String.valueOf(year) + "-" + String.valueOf(monthOfYear) + "-" + String.valueOf(dayOfMonth) + "\n"); } }, c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DATE)); case 4: // 弹出时间选择对话框 Calendar c2 = Calendar.getInstance(); return new TimePickerDialog(this, new OnTimeSetListener() { @Override public void onTimeSet(TimePicker view, int hourOfDay, int minute) { TextView txtMsg = (TextView) Main.this.findViewById(R.id.txtMsg); txtMsg.append("新设置的时间为：" + String.valueOf(hourOfDay) + ":" + String.valueOf(minute) + "\n"); } }, c2.get(Calendar.HOUR), c2.get(Calendar.MINUTE), true); case 5: // 弹出进度条对话框 ProgressDialog progress = new ProgressDialog(this); progress.setMessage("loading..."); return progress; default: return null; } }}

2、各种提示效果的演示 res/layout/main.xml

Android学习笔记总结代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <Button android:id="@+id/btn1" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn2" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn3" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> <Button android:id="@+id/btn4" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button> </LinearLayout>

res/layout/view.xml

Android学习笔记总结代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/txtMsg" android:layout_width="wrap_content" android:layout_height="wrap_content"> </TextView> </LinearLayout>

Main.java

Android学习笔记总结代码

package com.webabcd.notification; import android.app.Activity; import android.app.Notification; import android.app.NotificationManager; import android.app.PendingIntent; import android.content.Context; import android.content.Intent; import android.os.Bundle; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // 通过 Tost.makeText().show() 来实现提示性的通知效果 // 短时间的提示性通知的 Demo Button btn1 = (Button) this.findViewById(R.id.btn1); btn1.setText("短时间提示"); btn1.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { Toast.makeText(Main.this, "我是短时间提示", Toast.LENGTH_SHORT).show(); } }); // 长时间的提示性通知的 Demo Button btn2 = (Button) this.findViewById(R.id.btn2); btn2.setText("长时间提示"); btn2.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { Toast.makeText(Main.this, "我是长时间提示", Toast.LENGTH_LONG).show(); } }); // 以一个 View 作为提示性通知的 Demo Button btn3 = (Button) this.findViewById(R.id.btn3); btn3.setText("以一个 View 做提示"); btn3.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { View view = inflateView(R.layout.view); TextView txtMsg = (TextView) view.findViewById(R.id.txtMsg); txtMsg.setText("提示内容"); Toast toast = new Toast(Main.this); toast.setView(view); toast.setDuration(Toast.LENGTH_LONG); toast.show(); } }); Button btn4 = (Button) this.findViewById(R.id.btn4); btn4.setText("发出一个通知（Notification）"); btn4.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { // 实例化通知管理器 NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE); // 指定单击通知后所打开的详细的通知页面（单击通知后打开 NotificationView） PendingIntent contentIntent = PendingIntent.getActivity( Main.this, 0, new Intent(Main.this, NotificationView.class), 0); // 实例化一个通知，并指定其图标和标题（在提示栏上显示） Notification n = new Notification(R.drawable.icon01, "我是滚动的通知信息我是滚动的通知信息我是滚动的通知信息", System.currentTimeMillis()); // 设置通知的发送人和通知的详细内容（打开提示栏后在通知列表中显示） n.setLatestEventInfo(Main.this, "通知发送人", "我是详细的通知信息我是详细的通知信息我是详细的通知信息", contentIntent); // 100 毫秒延迟后，震动 250 毫秒，暂停 100 毫秒后，再震动 500 毫秒 n.vibrate = new long[] { 100, 250, 100, 500 }; // 发出通知（其中第一个参数为通知标识符） nm.notify(0, n); } }); } // 将指定的 xml 资源转换为一个 View private View inflateView(int resource) { LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE); return vi.inflate(resource, null); } // 打开详细通知页后此 Activity 会被 Pause，从详细通知页返回后此 Activity 会被 Resume @Override protected void onPause() { // TODO Auto-generated method stub super.onPause(); Log.d("MyDebug", "onPause"); } @Override protected void onResume() { // TODO Auto-generated method stub super.onResume(); Log.d("MyDebug", "onResume"); } }

NotificationView.java

Android学习笔记总结代码

package com.webabcd.notification; import android.app.Activity; import android.app.NotificationManager; import android.os.Bundle; import android.widget.TextView; // 单击通知列表的某个通知后，所打开的详细的通知页 public class NotificationView extends Activity { protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.view); TextView txtMsg = (TextView)this.findViewById(R.id.txtMsg); txtMsg.setText("点通知之后所链接到的 Activity"); NotificationManager nm = (NotificationManager) getSystemService(NOTIFICATION_SERVICE); // 取消显示在通知列表中的指定通知（参数为通知标识符） nm.cancel(0); // 需要关闭此 Activity 的话就 finish 它既可 // this.finish(); } }

Android(4) - 活动(Activity), 服务(Service), 广播(Broadcast), 广播接收器(BroadcastReceiver)

介绍

在 Android 中使用 Activity, Service, Broadcast, BroadcastReceiver

活动(Activity) - 用于表现功能

服务(Service) - 相当于后台运行的 Activity

广播(Broadcast) - 用于发送广播

广播接收器(BroadcastReceiver) - 用于接收广播

Intent - 用于连接以上各个组件，并在其间传递消息

1、演示 Activity 的基本用法，一个 Activity 启动另一个 Activity，启动另一个 Activity 时为其传递参数，被启动的 Activity 返回参数给启动者的 Activity

Main.java

代码

package com.webabcd.activity;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

public class Main extends Activity {

TextView txt;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

this.setContentView(R.layout.main);

txt = (TextView) this.findViewById(R.id.txt);

txt.setText("Activity 1");

Button btn = (Button) this.findViewById(R.id.btn);

btn.setText("启动另一个Activity");

btn.setOnClickListener(new Button.OnClickListener() {

@Override

public void onClick(View v) {

// 实例化 Intent，指定需要启动的 Activity

Intent intent = new Intent();

intent.setClass(Main.this, MyActivity.class);

// 实例化 Bundle，设置需要传递的参数

Bundle bundle = new Bundle();

bundle.putString("name", "webabcd");

bundle.putDouble("salary", 100.13);

// 将需要传递的参数赋值给 Intent 对象

intent.putExtras(bundle);

// startActivity(intent); // 启动指定的 Intent（不等待返回结果）

// Main.this.finish();

// 启动指定的 Intent，并等待返回结果

// 其中第二个参数如果大于等于零，则返回结果时会回调 onActivityResult() 方法

startActivityForResult(intent, 0);

}

});

Log.d("MyDebug", "onCreate");

}

// 被启动的 Activity 返回结果时的回调函数

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data) {

if (resultCode == Activity.RESULT_OK){

Bundle bundle = data.getExtras();

String name = bundle.getString("name");

double salary = bundle.getDouble("salary");

txt.setText("Activity 1" + "\n名字：" + name + "\n薪水：" + String.valueOf(salary));

}

@Override

protected void onStart() {

// TODO Auto-generated method stub

super.onStart();

Log.d("MyDebug", "onStart");

}

@Override

protected void onStop() {

// TODO Auto-generated method stub

super.onStop();

Log.d("MyDebug", "onStop");

}

@Override

protected void onRestart() {

// TODO Auto-generated method stub

super.onRestart();

Log.d("MyDebug", "onRestart");

}

@Override

protected void onPause() {

// TODO Auto-generated method stub

super.onPause();

Log.d("MyDebug", "onPause");

}

@Override

protected void onResume() {

// TODO Auto-generated method stub

super.onResume();

Log.d("MyDebug", "onResume");

}

@Override

protected void onDestroy() {

// TODO Auto-generated method stub

super.onDestroy();

Log.d("MyDebug", "onDestroy");

}

MyActivity.java

代码

package com.webabcd.activity;

import android.app.Activity;

import android.content.Intent;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.TextView;

// 被另一个 Activity 所启动的 Activity

public class MyActivity extends Activity {

Intent intent;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

this.setContentView(R.layout.main2);

// 获取启动者传递过来的参数

intent = this.getIntent();

Bundle bundle = intent.getExtras();

String name = bundle.getString("name");

double salary = bundle.getDouble("salary");

TextView txt = (TextView) this.findViewById(R.id.txt);

txt.setText("Activity 2" + "\n名字：" + name + "\n薪水：" + String.valueOf(salary));

Button btn = (Button) this.findViewById(R.id.btn);

btn.setText("返回前一个Activity");

btn.setOnClickListener(new Button.OnClickListener() {

public void onClick(View v) {

// 返回参数给启动者

MyActivity.this.setResult(Activity.RESULT_OK, intent);

MyActivity.this.finish();

}

});

}

AndroidManifest.xml

代码

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.webabcd.activity" android:versionCode="1"

android:versionName="1.0">

<intent-filter>

</intent-filter>

</activity>

<!--

如果有需要用到的 Activity ，则都要在这里做相应的配置

-->

</application>

<uses-sdk android:minSdkVersion="3" />

</manifest>

2、Service, Broadcast, BroadcastReceiver 的演示

Main.java

代码

package com.webabcd.service;

import android.app.Activity;

import android.content.BroadcastReceiver;

import android.content.ComponentName;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.content.ServiceConnection;

import android.os.Bundle;

import android.os.IBinder;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.TextView;

* startService() 和 bindService() 的区别

* startService() - 正常理解就好

* bindService() - 使当前上下文对象（本例中就是 Activity）通过一个 ServiceConnection 对象邦定到指定的 Service 。这样，如果上下文对象销毁了的话，那么其对应的 Service 也会被销毁

public class Main extends Activity implements OnClickListener {

private TextView txtMsg;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

setTitle("android 之 service");

this.findViewById(R.id.btnStart).setOnClickListener(this);

this.findViewById(R.id.btnStop).setOnClickListener(this);

this.findViewById(R.id.btnBind).setOnClickListener(this);

this.findViewById(R.id.btnUnbind).setOnClickListener(this);

txtMsg = (TextView)this.findViewById(R.id.txtMsg);

// 实例化自定义的 BroadcastReceiver

receiver = new UpdateReceiver();

IntentFilter filter = new IntentFilter();

// 为 BroadcastReceiver 指定 action ，使之用于接收同 action 的广播

filter.addAction("com.webabcd.service.msg");

// 以编程方式注册 BroadcastReceiver 。配置方式注册 BroadcastReceiver 的例子见 AndroidManifest.xml 文件

// 一般在 OnStart 时注册，在 OnStop 时取消注册

this.registerReceiver(receiver, filter);

// this.unregisterReceiver(receiver);

}

@Override

public void onClick(View v) {

Intent intent = new Intent(Main.this, MyService.class);

switch (v.getId()) {

case R.id.btnStart:

this.startService(intent);

break;

case R.id.btnStop:

this.stopService(intent);

break;

case R.id.btnBind:

this.bindService(intent, conn, Context.BIND_AUTO_CREATE);

break;

case R.id.btnUnbind:

this.unbindService(conn);

break;

}

// bindService() 所需的 ServiceConnection 对象

private ServiceConnection conn = new ServiceConnection() {

@Override

public void onServiceConnected(ComponentName className, IBinder service) {

}

@Override

public void onServiceDisconnected(ComponentName className) {

}

};

private String msg="";

private UpdateReceiver receiver;

// 实现一个 BroadcastReceiver，用于接收指定的 Broadcast

public class UpdateReceiver extends BroadcastReceiver{

@Override

public void onReceive(Context context, Intent intent) {

msg = intent.getStringExtra("msg");

txtMsg.append(msg + "\n");

}

MyService.java

代码

package com.webabcd.service;

import android.app.Service;

import android.content.Intent;

import android.os.IBinder;

import android.util.Log;

// 演示 Service 的生命周期。具体信息运行程序后在 LogCat 中查看

public class MyService extends Service {

@Override

public IBinder onBind(Intent intent) {

Log.d("MyDebug", "onBind");

sendMsg("onBind");

// TODO Auto-generated method stub

return null;

}

@Override

public void onCreate() {

// TODO Auto-generated method stub

super.onCreate();

Log.d("MyDebug", "onCreate");

sendMsg("onCreate");

}

@Override

public void onDestroy() {

// TODO Auto-generated method stub

super.onDestroy();

Log.d("MyDebug", "onDestroy");

sendMsg("onDestroy");

}

@Override

public void onRebind(Intent intent) {

// TODO Auto-generated method stub

super.onRebind(intent);

Log.d("MyDebug", "onRebind");

sendMsg("onRebind");

}

@Override

public void onStart(Intent intent, int startId) {

super.onStart(intent, startId);

Log.d("MyDebug", "onStart");

sendMsg("onStart");

}

@Override

public boolean onUnbind(Intent intent) {

Log.d("MyDebug", "onUnbind");

sendMsg("onUnbind");

// TODO Auto-generated method stub

return super.onUnbind(intent);

}

// 发送广播信息

private void sendMsg(String msg){

// 指定广播目标的 action （注：指定了此 action 的 receiver 会接收此广播）

Intent intent = new Intent("com.webabcd.service.msg");

// 需要传递的参数

intent.putExtra("msg", msg);

// 发送广播

this.sendBroadcast(intent);

}

MyBootReceiver.java

代码

package com.webabcd.service;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.util.Log;

public class MyBootReceiver extends BroadcastReceiver {

// 用于接收满足条件的 Broadcast（相应的 Broadcast 的注册信息详见 AndroidManifest.xml ，当系统启动完毕后会调用这个广播接收器）

@Override

public void onReceive(Context arg0, Intent arg1) {

Log.d("MyDebug", "onReceive");

// 启动服务

Intent service = new Intent(arg0, MyService.class);

arg0.startService(service);

}

AndroidManifest.xml

代码

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.webabcd.service" android:versionCode="1"

android:versionName="1.0">

<intent-filter>

</intent-filter>

</activity>

<!--

如果有需要用到的 service ，则都要在这里做相应的配置

-->

<!--

注册一个 BroadcastReceiver

其 intent-filter 为 android.intent.action.BOOT_COMPLETED（用于接收系统启动完毕的 Broadcast）

-->

<intent-filter>

</intent-filter>

</receiver>

</application>

<!--

接受系统启动完毕的 Broadcast 的权限

-->

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

<uses-sdk android:minSdkVersion="3" />

</manifest>

Android(5) - 控件(View)之TextView, Button, ImageButton, ImageView, CheckBox, RadioButton, AnalogClock, DigitalClock

介绍在 Android 中使用各种控件(View)

· TextView - 文本显示控件

· Button - 按钮控件

· ImageButton - 图片按钮控件

· ImageView - 图片显示控件

· CheckBox - 复选框控件

· RadioButton - 单选框控件

· AnalogClock - 钟表（带表盘的那种）控件

· DigitalClock - 电子表控件

1、TextView 的 Demo textview.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">  <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/textView" /> </LinearLayout>

_TextView.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class _TextView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.textview); // 设置 Activity 的标题 setTitle("TextView"); TextView txt = (TextView) this.findViewById(R.id.textView); // 设置文本显示控件的文本内容，需要换行的话就用“\n” txt.setText("我是 TextView\n显示文字用的"); } }

2、Button 的 Demo button.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/textView" />  <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content"> </Button> </LinearLayout>

_Button.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; public class _Button extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.button); setTitle("Button"); Button btn = (Button) this.findViewById(R.id.button); btn.setText("click me"); // setOnClickListener() - 响应按钮的鼠标单击事件 btn.setOnClickListener(new Button.OnClickListener(){ @Override public void onClick(View v) { TextView txt = (TextView) _Button.this.findViewById(R.id.textView); txt.setText("按钮被单击了"); } }); } }

3、ImageButton 的 Demo imagebutton.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/textView" />  <ImageButton android:id="@+id/imageButton" android:layout_width="wrap_content" android:layout_height="wrap_content"> </ImageButton> </LinearLayout>

_ImageButton.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.ImageButton; import android.widget.TextView; public class _ImageButton extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.imagebutton); setTitle("ImageButton"); ImageButton imgButton = (ImageButton) this.findViewById(R.id.imageButton); // 设置图片按钮的背景 imgButton.setBackgroundResource(R.drawable.icon01); // setOnClickListener() - 响应图片按钮的鼠标单击事件 imgButton.setOnClickListener(new Button.OnClickListener(){ @Override public void onClick(View v) { TextView txt = (TextView) _ImageButton.this.findViewById(R.id.textView); txt.setText("图片按钮被单击了"); } }); } }

4、ImageView 的 Demo imageview.xml

代码

_ImageView.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.ImageView; public class _ImageView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.imageview); setTitle("ImageView"); ImageView imgView = (ImageView) this.findViewById(R.id.imageView); // 指定需要显示的图片 imgView.setBackgroundResource(R.drawable.icon01); } }

5、CheckBox 的 Demo checkbox.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/textView" />  <CheckBox android:text="CheckBox01" android:id="@+id/chk1" android:layout_width="wrap_content" android:layout_height="wrap_content"></CheckBox> <CheckBox android:text="CheckBox02" android:id="@+id/chk2" android:layout_width="wrap_content" android:layout_height="wrap_content"></CheckBox> <CheckBox android:text="CheckBox03" android:id="@+id/chk3" android:layout_width="wrap_content" android:layout_height="wrap_content"></CheckBox> </LinearLayout>

_CheckBox.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.CheckBox; import android.widget.CompoundButton; import android.widget.TextView; public class _CheckBox extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.checkbox); setTitle("CheckBox"); CheckBox chk = (CheckBox) this.findViewById(R.id.chk1); // setOnCheckedChangeListener() - 响应复选框的选中状态改变事件 chk.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { TextView txt = (TextView) _CheckBox.this.findViewById(R.id.textView); txt.setText("CheckBox01 的选中状态：" + String.valueOf(isChecked)); } }); } }

6、RadioButton 的 Demo radiobutton.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/textView" />  <RadioGroup android:id="@+id/radioGroup" android:layout_width="fill_parent" android:layout_height="fill_parent" android:checkedButton="@+id/rad3" android:orientation="horizontal" android:gravity="center_vertical|center_horizontal"> <RadioButton android:text="rad1" android:id="@+id/rad1" android:layout_width="wrap_content" android:layout_height="wrap_content"></RadioButton> <RadioButton android:text="rad2" android:id="@+id/rad2" android:layout_width="wrap_content" android:layout_height="wrap_content"></RadioButton> <RadioButton android:text="rad3" android:id="@+id/rad3" android:layout_width="wrap_content" android:layout_height="wrap_content"></RadioButton> </RadioGroup> </LinearLayout>

_RadioButton.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.RadioButton; import android.widget.RadioGroup; import android.widget.TextView; public class _RadioButton extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.radiobutton); setTitle("RadioButton"); RadioGroup group = (RadioGroup) this.findViewById(R.id.radioGroup); // setOnCheckedChangeListener() - 响应单选框组内的选中项发生变化时的事件 group.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() { @Override public void onCheckedChanged(RadioGroup group, int checkedId) { TextView txt = (TextView) _RadioButton.this.findViewById(R.id.textView); txt.setText(((RadioButton)findViewById(checkedId)).getText() + " 被选中"); } }); } }

7、AnalogClock 的 Demo analogclock.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">  <AnalogClock android:id="@+id/analogClock" android:layout_width="wrap_content" android:layout_height="wrap_content"> </AnalogClock> </LinearLayout>

_AnalogClock.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; public class _AnalogClock extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.analogclcok); setTitle("AnalogClock"); } }

8、DigitalClock 的 Demo digitalclock.xml

代码

_DigitalClock.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; public class _DigitalClock extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.digitalclcok); setTitle("DigitalClcok"); } }

Android(6) - 控件(View)之DatePicker, TimePicker, ToggleButton, EditText, ProgressBar, SeekBar, AutoCompleteTextView, MultiAutoCompleteTextView

介绍在 Android 中使用各种控件(View)

· DatePicker - 日期选择控件

· TimePicker - 时间选择控件

· ToggleButton - 双状态按钮控件

· EditText - 可编辑文本控件

· ProgressBar - 进度条控件

· SeekBar - 可拖动的进度条控件

· AutoCompleteTextView - 支持自动完成功能的可编辑文本控件

· MultiAutoCompleteTextView - 支持自动完成功能的可编辑文本控件，允许输入多值（多值之间会自动地用指定的分隔符分开）

1、DatePicker 的 Demo datepicker.xml

代码

_DatePicker.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; public class _DatePicker extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.datepicker); // 具体的应用可参见对话框中的示例 setTitle("DatePicker"); } }

2、TimePicker 的 Demo timepicker.xml

代码

_TimePicker.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; public class _TimePicker extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.timepicker); // 具体的应用可参见对话框中的示例 setTitle("TimePicker"); } }

3、ToggleButton 的 Demo togglebutton.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/textView" />  <ToggleButton android:id="@+id/toggleButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textOn="关闭" android:textOff="打开" /> </LinearLayout>

_ToggleButton.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; import android.widget.ToggleButton; public class _ToggleButton extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.togglebutton); setTitle("ToggleButton"); final ToggleButton btn = (ToggleButton) this.findViewById(R.id.toggleButton); // setOnClickListener() - 响应按钮的鼠标单击事件 btn.setOnClickListener(new Button.OnClickListener(){ @Override public void onClick(View v) { TextView txt = (TextView) _ToggleButton.this.findViewById(R.id.textView); // ToggleButton.isChecked() - 双状态按钮的按钮状态 txt.setText("按钮状态：" + String.valueOf(btn.isChecked())); } }); } }

4、EditText 的 Demo edittext.xml

代码

_EditText.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.EditText; public class _EditText extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.edittext); setTitle("EditText"); EditText txt = (EditText) this.findViewById(R.id.editText); txt.setText("我可编辑"); } }

5、ProgressBar 的 Demo progressbar.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">   <ProgressBar android:id="@+android:id/progress_large" style="?android:attr/progressBarStyleLarge" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <ProgressBar android:id="@+android:id/progress" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <ProgressBar android:id="@+android:id/progress_small" style="?android:attr/progressBarStyleSmall" android:layout_width="wrap_content" android:layout_height="wrap_content" />  <ProgressBar android:id="@+id/progress_horizontal" style="?android:attr/progressBarStyleHorizontal" android:layout_width="200px" android:layout_height="wrap_content" android:max="100" android:progress="50" android:secondaryProgress="75" /> </LinearLayout>

_ProgressBar.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.view.Window; // 另见对话框中的进度条 public class _ProgressBar extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); // 设置特性以允许在应用程序的标题栏上显示进度条（条状） requestWindowFeature(Window.FEATURE_PROGRESS); // 设置特性以允许在应用程序的标题栏上显示进度条（圆圈状） requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS); this.setContentView(R.layout.progressbar); setTitle("ProgressBar"); // 在标题栏上显示进度条（条状） setProgressBarVisibility(true); // 在标题栏上显示进度条（圆圈状） setProgressBarIndeterminateVisibility(true); // 指定进度条的进度 setProgress(50 * 100); setSecondaryProgress(75 * 100); } }

6、SeekBar 的 Demo seekbar.xml

代码

_SeekBar.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.SeekBar; import android.widget.TextView; public class _SeekBar extends Activity implements SeekBar.OnSeekBarChangeListener { SeekBar mSeekBar; TextView mProgressText; TextView mTrackingText; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.seekbar); setTitle("SeekBar"); mSeekBar = (SeekBar) findViewById(R.id.seekBar); // setOnSeekBarChangeListener() - 响应拖动进度条事件 mSeekBar.setOnSeekBarChangeListener(this); mProgressText = (TextView) findViewById(R.id.progress); mTrackingText = (TextView) findViewById(R.id.tracking); } // 拖动进度条后，进度发生改变时的回调事件 public void onProgressChanged(SeekBar seekBar, int progress, boolean fromTouch) { mProgressText.setText(progress + "%"); } // 拖动进度条前开始跟踪触摸 public void onStartTrackingTouch(SeekBar seekBar) { mTrackingText.setText("开始跟踪触摸"); } // 拖动进度条后停止跟踪触摸 public void onStopTrackingTouch(SeekBar seekBar) { mTrackingText.setText("停止跟踪触摸"); } }

7、AutoCompleteTextView 的 Demo autocompletetextview.xml

代码

_AutoCompleteTextView.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.ArrayAdapter; import android.widget.AutoCompleteTextView; public class _AutoCompleteTextView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.autocompletetextview); setTitle("AutoCompleteTextView"); // 实例化适配器，指定显示格式及数据源 ArrayAdapter<String> adapter = new ArrayAdapter<String>( this, android.R.layout.simple_dropdown_item_1line, ary); AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.editText); // 指定自动完成控件的适配器 textView.setAdapter(adapter); } // 自动完成控件的所需数据的数据源 private String[] ary = new String[] { "abc", "abcd", "abcde", "abcdef", "abcdefg", "hij", "hijk", "hijkl", "hijklm", "hijklmn", }; }

8、MultiAutoCompleteTextView 的 Demo multiautocompletetextview.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">  <MultiAutoCompleteTextView android:id="@+id/editText" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>

_MultiAutoCompleteTextView.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.ArrayAdapter; import android.widget.MultiAutoCompleteTextView; public class _MultiAutoCompleteTextView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.multiautocompletetextview); setTitle("MultiAutoCompleteTextView"); // 实例化适配器，指定显示格式及数据源 ArrayAdapter<String> adapter = new ArrayAdapter<String>( this, android.R.layout.simple_dropdown_item_1line, ary); MultiAutoCompleteTextView textView = (MultiAutoCompleteTextView) findViewById(R.id.editText); textView.setAdapter(adapter); // 设置多个值之间的分隔符，此处为逗号 textView.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer()); } // 自动完成控件的所需数据的数据源 private String[] ary = new String[] { "abc", "abcd", "abcde", "abcdef", "abcdefg", "hij", "hijk", "hijkl", "hijklm", "hijklmn", }; }

Android(7) - 控件(View)之ZoomControls, Include, VideoView, WebView, RatingBar, Tab, Spinner, Chronometer, ScrollView

介绍在 Android 中使用各种控件(View)

· ZoomControls - 放大/缩小按钮控件

· Include - 整合控件

· VideoView - 视频播放控件

· WebView - 浏览器控件

· RatingBar - 评分控件

· Tab - 选项卡控件

· Spinner - 下拉框控件

· Chronometer - 计时器控件

· ScrollView - 滚动条控件

1、ZoomControls 的 Demo zoomcontrols.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">  <ZoomControls android:id="@+id/zoomControls" android:layout_width="wrap_content" android:layout_height="wrap_content"></ZoomControls> </LinearLayout>

_ZoomControls.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Toast; import android.widget.ZoomControls; public class _ZoomControls extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.zoomcontrols); setTitle("ZoomControls"); ZoomControls zoomControls = (ZoomControls) this.findViewById(R.id.zoomControls); // setOnZoomInClickListener() - 响应单击放大按钮的事件 zoomControls.setOnZoomInClickListener(new OnClickListener() { public void onClick(View v) { Toast.makeText(_ZoomControls.this, "单击了放大按钮", Toast.LENGTH_SHORT).show(); } }); // setOnZoomOutClickListener() - 响应单击缩小按钮的事件 zoomControls.setOnZoomOutClickListener(new OnClickListener() { public void onClick(View v) { Toast.makeText(_ZoomControls.this, "单击了缩小按钮", Toast.LENGTH_SHORT).show(); } }); } }

2、Include 的 Demo include.xml

代码

include_1.xml

代码

<?xml version="1.0" encoding="utf-8"?> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:text="TextView01" android:layout_width="wrap_content" android:layout_height="wrap_content"> </TextView>

include_2.xml

代码

<?xml version="1.0" encoding="utf-8"?> <TextView xmlns:android="http://schemas.android.com/apk/res/android" android:text="TextView02" android:layout_width="wrap_content" android:layout_height="wrap_content"> </TextView>

_Include.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; public class _Include extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.include); setTitle("Include"); } }

3、VideoView 的 Demo videoview.xml

代码

_VideoView.java

代码

package com.webabcd.view; import android.app.Activity; import android.net.Uri; import android.os.Bundle; import android.widget.MediaController; import android.widget.VideoView; public class _VideoView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.videoview); setTitle("VideoView"); VideoView videoView = (VideoView) findViewById(R.id.videoView); // 指定需要播放的视频的地址 videoView.setVideoURI(Uri.parse("android.resource://com.webabcd.view/" + R.raw.demo)); // videoView.setVideoPath(); // 设置播放器的控制条 videoView.setMediaController(new MediaController(this)); // 开始播放视频 videoView.start(); } }

4、WebView 的 Demo webview.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent">  <WebView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/webView" /> </LinearLayout>

_WebView.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.webkit.WebSettings; import android.webkit.WebView; public class _WebView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.webview); setTitle("WebView"); WebView webView = (WebView) findViewById(R.id.webView); // 配置浏览器，使其可支持 JavaScript WebSettings webSettings = webView.getSettings(); webSettings.setJavaScriptEnabled(true); // 清除浏览器缓存 webView.clearCache(true); // 指定浏览器需要解析的 url 地址 webView.loadUrl("http://webabcd.cnblogs.com/"); // 指定浏览器需要解析的 html 数据 // webView.loadData("<a href='http://webabcd.cnblogs.com/'>webabcd</a>", "text/html", "utf-8"); } }

5、RatingBar 的 Demo ratingbar.xml

代码

_RatingBar.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.RatingBar; import android.widget.TextView; public class _RatingBar extends Activity implements RatingBar.OnRatingBarChangeListener { private RatingBar mRatingBar; private TextView mTextView; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.ratingbar); setTitle("RatingBar"); mTextView = (TextView) findViewById(R.id.textView); mRatingBar = (RatingBar) findViewById(R.id.ratingBar); // setOnRatingBarChangeListener() - 响应评分值发生改变的事件 mRatingBar.setOnRatingBarChangeListener(this); } @Override public void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser) { mTextView.setText(String.valueOf(rating)); } }

6、Tab 的 Demo tab.xml

代码

<?xml version="1.0" encoding="utf-8"?> <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent">  <TextView android:id="@+id/view1" android:layout_width="fill_parent" android:layout_height="fill_parent" android:text="tab1 content" />  <TextView android:id="@+id/view2" android:layout_width="fill_parent" android:layout_height="fill_parent" android:text="tab2 content" /> </FrameLayout>

_Tab.java

代码

package com.webabcd.view; import android.app.TabActivity; import android.content.Intent; import android.os.Bundle; import android.view.LayoutInflater; import android.widget.TabHost; // 实现 Tab 功能的话要继承 TabActivity public class _Tab extends TabActivity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); TabHost tabHost = getTabHost(); LayoutInflater.from(this).inflate(R.layout.tab, tabHost.getTabContentView(), true); // Tab 1 的内容 tabHost.addTab(tabHost.newTabSpec("tab1") .setIndicator("tab1") .setContent(R.id.view1)); // Tab 2 的内容（设置了 Tab 图片） tabHost.addTab(tabHost.newTabSpec("tab2") .setIndicator("tab2", getResources().getDrawable(R.drawable.icon01)) .setContent(R.id.view2)); // Tab 3 的内容（设置 Tab 的内容为指定的 Activity） tabHost.addTab(tabHost.newTabSpec("tab3") .setIndicator("tab3") .setContent(new Intent(this, _TextView.class))); } }

7、Spinner 的 Demo spinner.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/textView" />  <Spinner android:id="@+id/spinner" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>

_Spinner.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Spinner; import android.widget.TextView; public class _Spinner extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.spinner); setTitle("Spinner"); Spinner spinner = (Spinner) findViewById(R.id.spinner); // 设置下拉框控件的标题文本 spinner.setPrompt("请选择"); // 实例化适配器，指定显示格式及数据源 ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource( this, R.array.colors, android.R.layout.simple_spinner_item); adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item); spinner.setAdapter(adapter); // setOnItemSelectedListener() - 响应下拉框的选中值发生变化的事件 spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) { TextView textView = (TextView)_Spinner.this.findViewById(R.id.textView); textView.setText(((TextView)arg1).getText()); } @Override public void onNothingSelected(AdapterView<?> arg0) { } }); } }

8、Chronometer 的 Demo chronometer.xml

代码

_Chronometer.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.os.SystemClock; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.Chronometer; public class _Chronometer extends Activity { private Chronometer mChronometer; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.chronometer); setTitle("Chronometer"); Button button; mChronometer = (Chronometer) findViewById(R.id.chronometer); // 设置计时器所显示的时间格式 mChronometer.setFormat("计时：(%s)"); button = (Button) findViewById(R.id.btnStart); button.setOnClickListener(mStartListener); button = (Button) findViewById(R.id.btnStop); button.setOnClickListener(mStopListener); button = (Button) findViewById(R.id.btnReset); button.setOnClickListener(mResetListener); } View.OnClickListener mStartListener = new OnClickListener() { public void onClick(View v) { // 启动计时器 mChronometer.start(); } }; View.OnClickListener mStopListener = new OnClickListener() { public void onClick(View v) { // 暂停计时器 mChronometer.stop(); } }; View.OnClickListener mResetListener = new OnClickListener() { public void onClick(View v) { // 复位计时器，即停止计时器 mChronometer.setBase(SystemClock.elapsedRealtime()); } }; }

9、ScrollView 的 Demo scrollview.xml

代码

_ScrollView.java

代码

package com.webabcd.view; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; public class _ScrollView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.scrollview); setTitle("ScrollView"); TextView textView = (TextView)this.findViewById(R.id.textView); textView.setText("a\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na\na"); } }

Android(8) - 控件(View)之TextSwitcher, Gallery, ImageSwitcher, GridView, ListView, ExpandableList

介绍在 Android 中使用各种控件(View)

· TextSwitcher - 文字转换器控件（改变文字时增加一些动画效果）

· Gallery - 缩略图浏览器控件

· ImageSwitcher - 图片转换器控件（改变图片时增加一些动画效果）

· GridView - 网格控件

· ListView - 列表控件

· ExpandableList - 支持展开/收缩功能的列表控件

1、TextSwitcher 的 Demo textswitcher.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <Button android:id="@+id/btnChange" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="改变文字" />  <TextSwitcher android:id="@+id/textSwitcher" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>

_TextSwitcher.java

代码

package com.webabcd.view; import java.util.Random; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.animation.Animation; import android.view.animation.AnimationUtils; import android.widget.Button; import android.widget.TextSwitcher; import android.widget.TextView; import android.widget.ViewSwitcher; public class _TextSwitcher extends Activity implements ViewSwitcher.ViewFactory { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.textswithcer); setTitle("TextSwithcer"); final TextSwitcher switcher = (TextSwitcher) findViewById(R.id.textSwitcher); // 指定转换器的 ViewSwitcher.ViewFactory switcher.setFactory(this); // 设置淡入和淡出的动画效果 Animation in = AnimationUtils.loadAnimation(this, android.R.anim.fade_in); Animation out = AnimationUtils.loadAnimation(this, android.R.anim.fade_out); switcher.setInAnimation(in); switcher.setOutAnimation(out); // 单击一次按钮改变一次文字 Button btnChange = (Button) this.findViewById(R.id.btnChange); btnChange.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { switcher.setText(String.valueOf(new Random().nextInt())); } }); } // 重写 ViewSwitcher.ViewFactory 的 makeView()，返回一个 View @Override public View makeView() { TextView textView = new TextView(this); textView.setTextSize(36); return textView; } }

2、Gallery 的 Demo gallery.xml

代码

_Gallery.java

代码

package com.webabcd.view; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.Gallery; import android.widget.ImageView; import android.widget.Toast; import android.widget.Gallery.LayoutParams; public class _Gallery extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.gallery); setTitle("Gallery"); Gallery gallery = (Gallery) findViewById(R.id.gallery); // 为缩略图浏览器指定一个适配器 gallery.setAdapter(new ImageAdapter(this)); // 响应在缩略图列表上选中某个缩略图后的事件 gallery.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> parent, View v, int position, long id) { Toast.makeText(_Gallery.this, String.valueOf(position), Toast.LENGTH_SHORT).show(); } @Override public void onNothingSelected(AdapterView<?> arg0) { } }); } // 继承 BaseAdapter 用以实现自定义的图片适配器 public class ImageAdapter extends BaseAdapter { private Context mContext; public ImageAdapter(Context context) { mContext = context; } public int getCount() { return mThumbIds.length; } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { ImageView image = new ImageView(mContext); image.setImageResource(mThumbIds[position]); image.setAdjustViewBounds(true); image.setLayoutParams(new Gallery.LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); return image; } } // 需要显示的图片集合 private Integer[] mThumbIds = { R.drawable.icon01, R.drawable.icon02, R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 }; }

3、ImageSwitcher 的 Demo imageswitcher.xml

代码

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <Gallery android:id="@+id/gallery" android:layout_width="fill_parent" android:layout_height="wrap_content" android:spacing="20px" />  <ImageSwitcher android:id="@+id/imageSwitcher" android:layout_width="fill_parent" android:layout_height="wrap_content" /> </LinearLayout>

_ImageSwitcher.java

代码

package com.webabcd.view; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.view.animation.AnimationUtils; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.Gallery; import android.widget.ImageSwitcher; import android.widget.ImageView; import android.widget.ViewSwitcher; import android.widget.Gallery.LayoutParams; // 图片转换器的使用基本同文字转换器 // 以下是一个用 ImageSwitcher + Gallery 实现的经典的图片浏览器的 Demo public class _ImageSwitcher extends Activity implements ViewSwitcher.ViewFactory { private ImageSwitcher mSwitcher; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.imageswithcer); setTitle("ImageSwithcer"); mSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher); mSwitcher.setFactory(this); mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in)); mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out)); Gallery gallery = (Gallery) findViewById(R.id.gallery); gallery.setAdapter(new ImageAdapter(this)); gallery.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() { @Override public void onItemSelected(AdapterView<?> parent, View v, int position, long id) { mSwitcher.setImageResource(mImageIds[position]); } @Override public void onNothingSelected(AdapterView<?> arg0) { } }); } public class ImageAdapter extends BaseAdapter { private Context mContext; public ImageAdapter(Context context) { mContext = context; } public int getCount() { return mThumbIds.length; } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { ImageView image = new ImageView(mContext); image.setImageResource(mThumbIds[position]); image.setAdjustViewBounds(true); image.setLayoutParams(new Gallery.LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); return image; } } private Integer[] mThumbIds = { R.drawable.icon01, R.drawable.icon02, R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 }; private Integer[] mImageIds = { R.drawable.icon01, R.drawable.icon02, R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 }; @Override public View makeView() { ImageView image = new ImageView(this); image.setMinimumHeight(200); image.setMinimumWidth(200); image.setScaleType(ImageView.ScaleType.FIT_CENTER); image.setLayoutParams(new ImageSwitcher.LayoutParams( LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); return image; } }

4、GridView 的 Demo gridview.xml

代码

<?xml version="1.0" encoding="utf-8"?>  <GridView xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/gridView" android:layout_width="fill_parent" android:layout_height="fill_parent" android:padding="10px" android:verticalSpacing="10px" android:horizontalSpacing="10px" android:numColumns="auto_fit" android:columnWidth="60px" android:stretchMode="columnWidth" android:gravity="center"> </GridView>

_GridView.java

代码

package com.webabcd.view; import android.app.Activity; import android.content.Context; import android.os.Bundle; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.GridView; import android.widget.ImageView; public class _GridView extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.setContentView(R.layout.gridview); setTitle("GridView"); GridView gridView = (GridView) findViewById(R.id.gridView); // 指定网格控件的适配器为自定义的图片适配器 gridView.setAdapter(new ImageAdapter(this)); } // 自定义的图片适配器 public class ImageAdapter extends BaseAdapter { private Context mContext; public ImageAdapter(Context context) { mContext = context; } public int getCount() { return mThumbIds.length; } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { ImageView imageView; if (convertView == null) { imageView = new ImageView(mContext); imageView.setLayoutParams(new GridView.LayoutParams(48, 48)); imageView.setAdjustViewBounds(false); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); imageView.setPadding(5, 5, 5, 5); } else { imageView = (ImageView) convertView; } imageView.setImageResource(mThumbIds[position]); return imageView; } // 网格控件所需图片数据的数据源 private Integer[] mThumbIds = { R.drawable.icon01, R.drawable.icon02, R.drawable.icon03, R.drawable.icon04, R.drawable.icon05 }; } }

5、ListView 的 Demo main_list_adapter.xml

代码

<?xml version="1.0" encoding="utf-8"?>  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent"> <TextView android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="16sp"> </TextView> </LinearLayout>

MainListAdapter.java

代码

package com.webabcd.view; import java.util.List; import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.TextView; // 继承 BaseAdapter 以实现自定义的列表适配器 public class MainListAdapter extends BaseAdapter { private LayoutInflater mInflater; private List<String> mData; public MainListAdapter(Context context, List<String> data) { mInflater = LayoutInflater.from(context); mData = data; } @Override public int getCount() { return mData.size(); } @Override public Object getItem(int position) { return mData.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { TextView text; if (convertView == null) { // 指定一个 layout 作为自定义列表适配器的 layout convertView = mInflater.inflate(R.layout.main_list_adapter, null); text = (TextView) convertView.findViewById(R.id.text); convertView.setTag(text); } else { text = (TextView) convertView.getTag(); } String mItem = mData.get(position); text.setText(mItem); return convertView; } }

Main.java

代码

package com.webabcd.view; import java.util.ArrayList; import java.util.List; import android.app.ListActivity; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.ListView; // 此处要继承 ListActivity ，用以实现 ListView 的功能 public class Main extends ListActivity { private List<String> mData; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setTheme(android.R.style.Theme_Light); setContentView(R.layout.main); mData = getData(); // 使用自定义的列表适配器来展现数据 MainListAdapter adapter = new MainListAdapter(this, mData); // 如需使用系统内置的列表适配器，则可以使用类似如下的方法 // ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_expandable_list_item_1, mData); this.setListAdapter(adapter); } // ListView 的数据源 private List<String> getData() { List<String> items = new ArrayList<String>(); items.add("TextView"); items.add("Button"); items.add("ImageButton"); items.add("ImageView"); items.add("CheckBox"); items.add("RadioButton"); items.add("AnalogClock"); items.add("DigitalClock"); items.add("DatePicker"); items.add("TimePicker"); items.add("ToggleButton"); items.add("EditText"); items.add("ProgressBar"); items.add("SeekBar"); items.add("AutoCompleteTextView"); items.add("MultiAutoCompleteTextView"); items.add("ZoomControls"); items.add("Include"); items.add("VideoView"); items.add("WebView"); items.add("RatingBar"); items.add("Tab"); items.add("Spinner"); items.add("Chronometer"); items.add("ScrollView"); items.add("TextSwitcher"); items.add("ListView"); items.add("Gallery"); items.add("ImageSwitcher"); items.add("GridView"); items.add("ExpandableList"); return items; } // ListView 中某项被选中后的逻辑 @Override protected void onListItemClick(ListView l, View v, int position, long id) { Intent intent = new Intent(); intent.setClassName(this, "com.webabcd.view._" + mData.get(position)); startActivityForResult(intent, 0); } }

6、ExpandableList 的 Demo _ExpandableList.java

代码

package com.webabcd.view; import android.app.ExpandableListActivity; import android.os.Bundle; import android.view.ContextMenu; import android.view.Gravity; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.view.ContextMenu.ContextMenuInfo; import android.widget.AbsListView; import android.widget.BaseExpandableListAdapter; import android.widget.ExpandableListAdapter; import android.widget.ExpandableListView; import android.widget.TextView; import android.widget.Toast; import android.widget.ExpandableListView.ExpandableListContextMenuInfo; // ExpandableList - 可展开/收缩列表 // 继承 ExpandableListActivity 以实现列表的可展开/收缩的功能 public class _ExpandableList extends ExpandableListActivity { private ExpandableListAdapter mAdapter; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setTitle("ExpandableList"); mAdapter = new MyExpandableListAdapter(); setListAdapter(mAdapter); registerForContextMenu(this.getExpandableListView()); } // 为列表的每一项创建上下文菜单（即长按后呼出的菜单） @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { menu.setHeaderTitle("ContextMenu"); menu.add(0, 0, 0, "ContextMenu"); } // 单击上下文菜单后的逻辑 @Override public boolean onContextItemSelected(MenuItem item) { ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo(); String title = ((TextView) info.targetView).getText().toString(); int type = ExpandableListView.getPackedPositionType(info.packedPosition); if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) { int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition); Toast.makeText(this, title + " - Group Index: " + groupPos + " Child Index: " + childPos, Toast.LENGTH_SHORT).show(); return true; } else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) { int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); Toast.makeText(this, title + " - Group Index: " + groupPos, Toast.LENGTH_SHORT).show(); return true; } return false; } public class MyExpandableListAdapter extends BaseExpandableListAdapter { // 父列表数据 private String[] groups = { "group1", "group2", "group3", "group4" }; // 子列表数据 private String[][] children = { { "child1" }, { "child1", "child2" }, { "child1", "child2", "child3" }, { "child1", "child2", "child3", "child4" } }; @Override public Object getChild(int groupPosition, int childPosition) { return children[groupPosition][childPosition]; } @Override public long getChildId(int groupPosition, int childPosition) { return childPosition; } @Override public int getChildrenCount(int groupPosition) { return children[groupPosition].length; } // 取子列表中的某一项的 View @Override public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) { TextView textView = getGenericView(); textView.setText(getChild(groupPosition, childPosition).toString()); return textView; } @Override public Object getGroup(int groupPosition) { return groups[groupPosition]; } @Override public int getGroupCount() { return groups.length; } @Override public long getGroupId(int groupPosition) { return groupPosition; } // 取父列表中的某一项的 View @Override public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { TextView textView = getGenericView(); textView.setText(getGroup(groupPosition).toString()); return textView; } @Override public boolean hasStableIds() { return true; } @Override public boolean isChildSelectable(int groupPosition, int childPosition) { return true; } // 获取某一项的 View 的逻辑 private TextView getGenericView() { AbsListView.LayoutParams lp = new AbsListView.LayoutParams( ViewGroup.LayoutParams.FILL_PARENT, 48); TextView textView = new TextView(_ExpandableList.this); textView.setLayoutParams(lp); textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT); textView.setPadding(32, 0, 0, 0); return textView; } } }

Android(9) - 数据库支持(SQLite), 内容提供器(ContentProvider)

介绍在 Android 中使用 SQLite, ContentProvider

· 数据库支持(SQLite) - Android 开发平台提供了操作 SQLite 数据库的相关 API

· 内容提供器(ContentProvider) - 当数据需要在应用程序之间共享时，可以在某程序中使用 ContentProvider 定义 URI，以使其它应用程序可以通过此 URI 访问指定的数据

1、SQLite 的 Demo DatabaseHelper.java

代码

package com.webabcd.SQLite; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.database.sqlite.SQLiteDatabase.CursorFactory; // 数据库操作的 Helper 类 public class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context, String name, CursorFactory cursorFactory, int version) { super(context, name, cursorFactory, version); } @Override public void onCreate(SQLiteDatabase db) { // TODO 创建数据库后，对数据库的操作 } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO 更改数据库版本的操作 } @Override public void onOpen(SQLiteDatabase db) { super.onOpen(db); // TODO 每次成功打开数据库后首先被执行 } }

Main.java

代码

package com.webabcd.SQLite; import java.util.Random; import android.app.Activity; import android.content.ContentValues; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; public class Main extends Activity { private DatabaseHelper dbHelper; private static final String DATABASE_NAME = "db.db"; private static final int DATABASE_VERSION = 1; private static final String TABLE_NAME = "employee"; TextView txtMsg; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); dbHelper = new DatabaseHelper(this, DATABASE_NAME, null, DATABASE_VERSION); txtMsg = (TextView) this.findViewById(R.id.txtMsg); Button btn1 = (Button) this.findViewById(R.id.btn1); btn1.setText("创建表"); btn1.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { CreateTable(); } }); Button btn2 = (Button) this.findViewById(R.id.btn2); btn2.setText("插入 3 条记录"); btn2.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { insertItem(); } }); Button btn3 = (Button) this.findViewById(R.id.btn3); btn3.setText("删除全部记录"); btn3.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { deleteItem(); } }); Button btn4 = (Button) this.findViewById(R.id.btn4); btn4.setText("更新指定数据"); btn4.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { updateItem(); } }); Button btn5 = (Button) this.findViewById(R.id.btn5); btn5.setText("显示全部数据"); btn5.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { showItems(); } }); Button btn6 = (Button) this.findViewById(R.id.btn6); btn6.setText("删除表"); btn6.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { dropTable(); } }); } // 创建数据表 private void CreateTable() { SQLiteDatabase db = dbHelper.getWritableDatabase(); String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_NAME + " (ID INTEGER PRIMARY KEY, Name VARCHAR, Age INTEGER);"; try { db.execSQL(sql); txtMsg.append("数据表成功创建\n"); } catch (SQLException ex) { txtMsg.append("数据表创建错误\n" + ex.toString() + "\n"); } } // 插入数据 private void insertItem() { SQLiteDatabase db = dbHelper.getWritableDatabase(); try { Random random = new Random(); for (int i = 0; i < 3; i++) { String sql = "insert into " + TABLE_NAME + " (name, age) values ('name" + String.valueOf(i) + "', " + random.nextInt() + ")"; // execSQL() - 执行指定的 sql db.execSQL(sql); } txtMsg.append("成功插入 3 条数据\n"); } catch (SQLException ex) { txtMsg.append("插入数据失败\n" + ex.toString() + "\n"); } } // 删除数据 private void deleteItem() { try { SQLiteDatabase db = dbHelper.getWritableDatabase(); db.delete(TABLE_NAME, " id < 999999", null); txtMsg.append("成功删除数据\n"); } catch (SQLException e) { txtMsg.append("删除数据失败\n"); } } // 更新数据 private void updateItem() { SQLiteDatabase db = dbHelper.getWritableDatabase(); try { ContentValues values = new ContentValues(); values.put("name", "批量更新后的名字"); db.update(TABLE_NAME, values, "id<?", new String[] { "3" }); txtMsg.append("成功更新数据\n"); } catch (SQLException e) { txtMsg.append("更新数据失败\n"); } } // 查询数据 private void showItems() { SQLiteDatabase db = dbHelper.getReadableDatabase(); try { String[] column = { "id", "name", "age" }; Cursor cursor = db.query(TABLE_NAME, column, null, null, null, null, null); Integer num = cursor.getCount(); txtMsg.append("共 " + Integer.toString(num) + " 条记录\n"); cursor.moveToFirst(); while (cursor.getPosition() != cursor.getCount()) { txtMsg.append(Integer.toString(cursor.getPosition()) + "," + String.valueOf(cursor.getString(0)) + "," + cursor.getString(1) + "," + String.valueOf(cursor.getString(2)) + "\n"); cursor.moveToNext(); } } catch (SQLException ex) { txtMsg.append("读取数据失败\n" + ex.toString() + "\n"); } } // 删除数据表 private void dropTable() { SQLiteDatabase db = dbHelper.getWritableDatabase(); String sql = "DROP TABLE IF EXISTS " + TABLE_NAME; try { db.execSQL(sql); txtMsg.append("数据表删除成功\n"); } catch (SQLException ex) { txtMsg.append("数据表删除错误\n" + ex.toString() + "\n"); } } }

2、ContentProvider 的 Demo MyUser.java

代码

package com.webabcd.contentprovider; import android.net.Uri; import android.provider.BaseColumns; // 自定义 ContentProvider 所需的实体类 public class MyUser { // 必须要有 _id 字段。本例中 BaseColumn 类中已经包含了 _id 字段 public static final class User implements BaseColumns { // 定义 CONTENT_URI public static final Uri CONTENT_URI = Uri.parse("content://com.webabcd.MyContentProvider"); // 表数据列 public static final String USER_NAME = "USER_NAME"; } }

MyContentProvider.java

代码

package com.webabcd.contentprovider; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import org.apache.http.util.EncodingUtils; import android.content.ContentProvider; import android.content.ContentUris; import android.content.ContentValues; import android.database.Cursor; import android.database.MatrixCursor; import android.net.Uri; // 继承 ContentProvider 以实现自定义的 ContentProvider（基于文件的信息存储） public class MyContentProvider extends ContentProvider { private File file; private FileOutputStream out; private FileInputStream in; // ContentProvider 的删除数据接口 @Override public int delete(Uri uri, String selection, String[] selectionArgs) { // TODO Auto-generated method stub return 0; } @Override public String getType(Uri uri) { // TODO Auto-generated method stub return null; } // ContentProvider 的插入数据接口 @Override public Uri insert(Uri uri, ContentValues values) { try { out = new FileOutputStream(file); out.write(values.getAsString(MyUser.User.USER_NAME).getBytes()); out.close(); int rowId = 0; Uri rowUri = ContentUris.appendId( MyUser.User.CONTENT_URI.buildUpon(), rowId).build(); getContext().getContentResolver().notifyChange(rowUri, null); return rowUri; } catch (Exception e) { return null; } } // 创建用于保存信息的文件 @Override public boolean onCreate() { try { // 每个包中应用程序的私有目录为：/data/data/包名/ // SD 卡目录为：/sdcard file = new File("/data/data/com.webabcd.contentprovider/", "demo.txt"); if (!file.exists()) file.createNewFile(); return true; } catch (Exception ex) { return false; } } // ContentProvider 的查询数据接口 @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { String content; try { in = new FileInputStream(file); int length = (int) file.length(); byte[] buffer = new byte[length]; in.read(buffer, 0, length); content = EncodingUtils.getString(buffer, "UTF-8"); in.close(); String[] columns = new String[] { MyUser.User._ID, MyUser.User.USER_NAME }; MatrixCursor cur = new MatrixCursor(columns); String[] values = new String[] { "0", content }; cur.moveToFirst(); cur.addRow(values); return cur; } catch (Exception e) { return null; } } // ContentProvider 的更新数据接口 @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { // TODO Auto-generated method stub return 0; } }

Main.java

代码

的联系人记录） */ public class Main extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button btn1 = (Button) this.findViewById(R.id.btn1); btn1.setText("新增联系人记录"); btn1.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { Random random = new Random(); insertRecords("name" + String.valueOf(random.nextInt()), String .valueOf(random.nextInt())); } }); Button btn2 = (Button) this.findViewById(R.id.btn2); btn2.setText("查看联系人记录"); btn2.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { displayRecords(); } }); Button btn3 = (Button) this.findViewById(R.id.btn3); btn3.setText("清除联系人记录"); btn3.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { deleteRecords(); } }); Button btn4 = (Button) this.findViewById(R.id.btn4); btn4.setText("更新联系人记录"); btn4.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { // 此处只是演示，id 来自 People._ID ，可参见 displayRecords() 是如何获取 id 的 int id = 0; updateRecord(id, "修改后的name"); } }); Button btn5 = (Button) this.findViewById(R.id.btn5); btn5.setText("新增记录到 MyContentProvider"); btn5.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { insertRecord2MyContentProvider("webabcd"); } }); Button btn6 = (Button) this.findViewById(R.id.btn6); btn6.setText("获取记录从 MyContentProvider"); btn6.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { displayRecord2MyContentProvider(); } }); } // 调用 ContentProvider 的插入接口 private void insertRecords(String name, String phoneNum) { ContentValues values = new ContentValues(); values.put(People.NAME, name); Uri uri = getContentResolver().insert(People.CONTENT_URI, values); Log.d("MyDebug", uri.toString()); Uri numberUri = Uri.withAppendedPath(uri, People.Phones.CONTENT_DIRECTORY); Log.d("MyDebug", numberUri.toString()); values.clear(); values.put(Contacts.Phones.TYPE, People.Phones.TYPE_MOBILE); values.put(People.NUMBER, phoneNum); getContentResolver().insert(numberUri, values); } // 调用 ContentProvider 的查询接口 private void displayRecords() { String[] columns = new String[] { People._ID, People.NAME, People.NUMBER }; Uri contacts = People.CONTENT_URI; Log.d("MyDebug", contacts.toString()); Cursor cur = managedQuery(contacts, columns, // 要返回的数据字段 null, // WHERE子句 null, // WHERE 子句的参数 null // Order-by子句 ); if (cur.moveToFirst()) { String id = null; String name = null; String phoneNo = null; while (cur.getPosition() != cur.getCount()) { id = cur.getString(cur.getColumnIndex(People._ID)); name = cur.getString(cur.getColumnIndex(People.NAME)); phoneNo = cur.getString(cur.getColumnIndex(People.NUMBER)); Toast.makeText(this, id + " / " + name + " / " + phoneNo, Toast.LENGTH_SHORT).show(); cur.moveToNext(); } } } // 调用 ContentProvider 的删除接口 private void deleteRecords() { Uri uri = People.CONTENT_URI; Log.d("MyDebug", uri.toString()); getContentResolver().delete(uri, null, null); // getContentResolver().delete(uri, "NAME=" + "'name'", null); } // 调用 ContentProvider 的更新接口 private void updateRecord(int recordNo, String name) { Uri uri = ContentUris.withAppendedId(People.CONTENT_URI, recordNo); Log.d("MyDebug", uri.toString()); ContentValues values = new ContentValues(); values.put(People.NAME, name); getContentResolver().update(uri, values, null, null); } // 调用自定义 ContentProvider 的插入接口 private void insertRecord2MyContentProvider(String name) { ContentValues values = new ContentValues(); values.put(MyUser.User.USER_NAME, name); getContentResolver().insert(MyUser.User.CONTENT_URI, values); } // 调用自定义 ContentProvider 的查询接口 private void displayRecord2MyContentProvider() { String[] columns = new String[] { MyUser.User.USER_NAME }; Uri uri = MyUser.User.CONTENT_URI; Cursor cur = managedQuery(uri, columns, null, null, null); while (cur.getPosition() != cur.getCount()) { String id = cur.getString(cur.getColumnIndex(People._ID)); String name = cur.getString(cur.getColumnIndex(MyUser.User.USER_NAME)); Toast.makeText(this, id + " / " + name, Toast.LENGTH_SHORT).show(); cur.moveToNext(); } } }

AndroidManifest.xml

代码

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.webabcd.contentprovider" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name"> <activity android:name=".Main" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity>  <provider android:name="MyContentProvider" android:authorities="com.webabcd.MyContentProvider" /> </application> <uses-permission android:name="android.permission.WRITE_CONTACTS"></uses-permission> <uses-permission android:name="android.permission.READ_CONTACTS"></uses-permission> <uses-sdk android:minSdkVersion="3" /> </manifest>

Android(10) - HTTP 通信, XML 解析, 通过 Hander 实现异步消息处理

介绍在 Android 中与服务端做 HTTP 通信，解析 XML，通过 Handler 实现异步消息处理

· HTTP 通信 - 与服务端做 HTTP 通信，分别以 GET 方式和 POST 方式做演示

· XML 解析 - 可以用两种方式解析 XML，分别是 DOM 方式和 SAX 方式

· 异步消息处理 - 通过 Handler 实现异步消息处理，以一个自定义的异步下载类来说明 Handler 的用法

1、HTTP 通信和 XML 解析的 Demo MySAXHandler.java

代码

package com.webabcd.communication; import org.xml.sax.Attributes; import org.xml.sax.SAXException; import org.xml.sax.helpers.DefaultHandler; // 继承 DefaultHandler 以实现指定 XML 的 SAX 解析器 // DOM - W3C 标准，需要把 xml 数据全部加载完成后才能对其做解析，可对树做任意遍历 // SAX - 流式解析，通过事件模型解析 xml，只能顺序解析 public class MySAXHandler extends DefaultHandler { private boolean mIsTitleTag = false; private boolean mIsSalaryTag = false; private boolean mIsBirthTag = false; private String mResult = ""; // 打开 xml 文档的回调函数 @Override public void startDocument() throws SAXException { // TODO Auto-generated method stub super.startDocument(); } // 关闭 xml 文档的回调函数 @Override public void endDocument() throws SAXException { // TODO Auto-generated method stub super.endDocument(); } // 一发现元素开始标记就回调此函数 @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { if (localName == "title") mIsTitleTag = true; else if (localName == "salary") mIsSalaryTag = true; else if (localName == "dateOfBirth") mIsBirthTag = true; else if (localName == "employee") mResult += "\nname:" + attributes.getValue("name"); } // 一发现元素结束标记就回调此函数 @Override public void endElement(String uri, String localName, String qName) throws SAXException { if (localName == "title") mIsTitleTag = false; else if (localName == "salary") mIsSalaryTag = false; else if (localName == "dateOfBirth") mIsBirthTag = false; } // 一发现元素值或属性值就回调此函数 @Override public void characters(char[] ch, int start, int length) throws SAXException { if (mIsTitleTag) mResult += new String(ch, start, length); else if (mIsSalaryTag) mResult += " salary:" + new String(ch, start, length); else if (mIsBirthTag) mResult += " dateOfBirth:" + new String(ch, start, length); } public String getResult(){ return mResult; } }

Main.java

代码

package com.webabcd.communication; import java.io.BufferedInputStream; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLConnection; import java.util.ArrayList; import java.util.HashMap; import java.util.Map; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.SAXParser; import javax.xml.parsers.SAXParserFactory; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import org.apache.http.protocol.HTTP; import org.apache.http.util.ByteArrayBuffer; import org.apache.http.util.EncodingUtils; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NodeList; import org.xml.sax.InputSource; import org.xml.sax.XMLReader; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.TextView; public class Main extends Activity { private TextView textView; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); textView = (TextView) this.findViewById(R.id.textView); Button btn1 = (Button) this.findViewById(R.id.btn1); btn1.setText("http get demo"); btn1.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { httpGetDemo(); } }); Button btn2 = (Button) this.findViewById(R.id.btn2); btn2.setText("http post demo"); btn2.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { httpPostDemo(); } }); Button btn3 = (Button) this.findViewById(R.id.btn3); // DOM - Document Object Model btn3.setText("DOM 解析 XML"); btn3.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { DOMDemo(); } }); Button btn4 = (Button) this.findViewById(R.id.btn4); // SAX - Simple API for XML btn4.setText("SAX 解析 XML"); btn4.setOnClickListener(new Button.OnClickListener() { public void onClick(View v) { SAXDemo(); } }); } // Android 调用 http 协议的 get 方法 // 本例：以 http 协议的 get 方法获取远程页面响应的内容 private void httpGetDemo(){ try { // 模拟器测试时，请使用外网地址 URL url = new URL("http://xxx.xxx.xxx"); URLConnection con = url.openConnection(); String result = "http status code: " + ((HttpURLConnection)con).getResponseCode() + "\n"; // HttpURLConnection.HTTP_OK InputStream is = con.getInputStream(); BufferedInputStream bis = new BufferedInputStream(is); ByteArrayBuffer bab = new ByteArrayBuffer(32); int current = 0; while ( (current = bis.read()) != -1 ){ bab.append((byte)current); } result += EncodingUtils.getString(bab.toByteArray(), HTTP.UTF_8); bis.close(); is.close(); textView.setText(result); } catch (Exception e) { textView.setText(e.toString()); } } // Android 调用 http 协议的 post 方法 // 本例：以 http 协议的 post 方法向远程页面传递参数，并获取其响应的内容 private void httpPostDemo(){ try { // 模拟器测试时，请使用外网地址 String url = "http://5billion.com.cn/post.php"; Map<String, String> data = new HashMap<String, String>(); data.put("name", "webabcd"); data.put("salary", "100"); DefaultHttpClient httpClient = new DefaultHttpClient(); HttpPost httpPost = new HttpPost(url); ArrayList<BasicNameValuePair> postData = new ArrayList<BasicNameValuePair>(); for (Map.Entry<String, String> m : data.entrySet()) { postData.add(new BasicNameValuePair(m.getKey(), m.getValue())); } UrlEncodedFormEntity entity = new UrlEncodedFormEntity(postData, HTTP.UTF_8); httpPost.setEntity(entity); HttpResponse response = httpClient.execute(httpPost); String result = "http status code: " + response.getStatusLine().getStatusCode() + "\n"; // HttpURLConnection.HTTP_OK HttpEntity httpEntity = response.getEntity(); InputStream is = httpEntity.getContent(); result += convertStreamToString(is); textView.setText(result); } catch (Exception e) { textView.setText(e.toString()); } } // 以 DOM 方式解析 XML（xml 数据详见 res/raw/employee.xml） private void DOMDemo(){ try { DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance(); DocumentBuilder docBuilder = docFactory.newDocumentBuilder(); Document doc = docBuilder.parse(this.getResources().openRawResource(R.raw.employee)); Element rootElement = doc.getDocumentElement(); NodeList employeeNodeList = rootElement.getElementsByTagName("employee"); textView.setText("DOMDemo" + "\n"); String title = rootElement.getElementsByTagName("title").item(0).getFirstChild().getNodeValue(); textView.append(title); for (int i=0; i<employeeNodeList.getLength(); i++){ Element employeeElement = ((Element)employeeNodeList.item(i)); String name = employeeElement.getAttribute("name"); String salary = employeeElement.getElementsByTagName("salary").item(0).getFirstChild().getNodeValue(); String dateOfBirth = employeeElement.getElementsByTagName("dateOfBirth").item(0).getFirstChild().getNodeValue(); textView.append("\nname: "+name+" salary: "+salary+" dateOfBirth: " + dateOfBirth); } } catch (Exception e) { textView.setText(e.toString()); } } // 以 SAX 方式解析 XML（xml 数据详见 res/raw/employee.xml） // SAX 解析器的实现详见 MySAXHandler.java private void SAXDemo(){ try { SAXParserFactory saxFactory = SAXParserFactory.newInstance(); SAXParser parser = saxFactory.newSAXParser(); XMLReader reader = parser.getXMLReader(); MySAXHandler handler = new MySAXHandler(); reader.setContentHandler(handler); reader.parse(new InputSource(this.getResources().openRawResource(R.raw.employee))); String result = handler.getResult(); textView.setText("SAXDemo" + "\n"); textView.append(result); } catch (Exception e) { textView.setText(e.toString()); } } // 辅助方法，用于把流转换为字符串 private String convertStreamToString(InputStream is) { BufferedReader reader = new BufferedReader(new InputStreamReader(is)); StringBuilder sb = new StringBuilder(); String line = null; try { while ((line = reader.readLine()) != null) { sb.append(line + "\n"); } } catch (IOException e) { e.printStackTrace(); } finally { try { is.close(); } catch (IOException e) { e.printStackTrace(); } } return sb.toString(); }}

2、用 Handler 来实现异步消息处理，以一个可以实时汇报下载进度的异步下载类为例开发一个 Android 类库，本例中此类库名为 webabcd_util New -> Java Project 项目上点右键 -> Build Path -> Add Libraries -> User Library -> User Libraries -> New -> 为类库起个名字 -> 选中这个类库 -> Add JARs 导入 Android 的 jar 包项目上点右键 -> Build Path -> Add Libraries -> User Library -> 选择 Android 库 DownloadManagerAsync.java

代码

package webabcd.util; import java.io.BufferedReader; import java.io.File; import java.io.FileOutputStream; import java.io.InputStream; import java.io.InputStreamReader; import java.net.URL; import java.net.URLConnection; import org.apache.http.protocol.HTTP; import android.os.Handler; import android.os.Message; import android.util.Log; // 以一个实例，即异步下载，来演示 Android 的异步消息处理（用 Handler 的方式） public class DownloadManagerAsync { public DownloadManagerAsync() { } // 实例化自定义的 Handler EventHandler mHandler = new EventHandler(this); // 按指定 url 地址下载文件到指定路径 public void download(final String url, final String savePath) { new Thread(new Runnable() { public void run() { try { sendMessage(FILE_DOWNLOAD_CONNECT); URL sourceUrl = new URL(url); URLConnection conn = sourceUrl.openConnection(); InputStream inputStream = conn.getInputStream(); int fileSize = conn.getContentLength(); File savefile = new File(savePath); if (savefile.exists()) { savefile.delete(); } savefile.createNewFile(); FileOutputStream outputStream = new FileOutputStream( savePath, true); byte[] buffer = new byte[1024]; int readCount = 0; int readNum = 0; int prevPercent = 0; while (readCount < fileSize && readNum != -1) { readNum = inputStream.read(buffer); if (readNum > -1) { outputStream.write(buffer); readCount = readCount + readNum; int percent = (int) (readCount * 100 / fileSize); if (percent > prevPercent) { // 发送下载进度信息 sendMessage(FILE_DOWNLOAD_UPDATE, percent, readCount); prevPercent = percent; } } } outputStream.close(); sendMessage(FILE_DOWNLOAD_COMPLETE, savePath); } catch (Exception e) { sendMessage(FILE_DOWNLOAD_ERROR, e); Log.e("MyError", e.toString()); } } }).start(); } // 读取指定 url 地址的响应内容 public void download(final String url) { new Thread(new Runnable() { public void run() { try { sendMessage(FILE_DOWNLOAD_CONNECT); URL sourceUrl = new URL(url); URLConnection conn = sourceUrl.openConnection(); conn.setConnectTimeout(3000); BufferedReader reader = new BufferedReader( new InputStreamReader(conn.getInputStream(), HTTP.UTF_8)); String line = null; StringBuffer content = new StringBuffer(); while ((line = reader.readLine()) != null) { content.append(line); } reader.close(); sendMessage(FILE_DOWNLOAD_COMPLETE, content.toString()); } catch (Exception e) { sendMessage(FILE_DOWNLOAD_ERROR, e); Log.e("MyError", e.toString()); } } }).start(); } // 向 Handler 发送消息 private void sendMessage(int what, Object obj) { // 构造需要向 Handler 发送的消息 Message msg = mHandler.obtainMessage(what, obj); // 发送消息 mHandler.sendMessage(msg); } private void sendMessage(int what) { Message msg = mHandler.obtainMessage(what); mHandler.sendMessage(msg); } private void sendMessage(int what, int arg1, int arg2) { Message msg = mHandler.obtainMessage(what, arg1, arg2); mHandler.sendMessage(msg); } private static final int FILE_DOWNLOAD_CONNECT = 0; private static final int FILE_DOWNLOAD_UPDATE = 1; private static final int FILE_DOWNLOAD_COMPLETE = 2; private static final int FILE_DOWNLOAD_ERROR = -1; // 自定义的 Handler private class EventHandler extends Handler { private DownloadManagerAsync mManager; public EventHandler(DownloadManagerAsync manager) { mManager = manager; } // 处理接收到的消息 @Override public void handleMessage(Message msg) { switch (msg.what) { case FILE_DOWNLOAD_CONNECT: if (mOnDownloadConnectListener != null) mOnDownloadConnectListener.onDownloadConnect(mManager); break; case FILE_DOWNLOAD_UPDATE: if (mOnDownloadUpdateListener != null) mOnDownloadUpdateListener.onDownloadUpdate(mManager, msg.arg1); break; case FILE_DOWNLOAD_COMPLETE: if (mOnDownloadCompleteListener != null) mOnDownloadCompleteListener.onDownloadComplete(mManager, msg.obj); break; case FILE_DOWNLOAD_ERROR: if (mOnDownloadErrorListener != null) mOnDownloadErrorListener.onDownloadError(mManager, (Exception) msg.obj); break; default: break; } } } // 定义连接事件 private OnDownloadConnectListener mOnDownloadConnectListener; public interface OnDownloadConnectListener { void onDownloadConnect(DownloadManagerAsync manager); } public void setOnDownloadConnectListener(OnDownloadConnectListener listener) { mOnDownloadConnectListener = listener; } // 定义下载进度更新事件 private OnDownloadUpdateListener mOnDownloadUpdateListener; public interface OnDownloadUpdateListener { void onDownloadUpdate(DownloadManagerAsync manager, int percent); } public void setOnDownloadUpdateListener(OnDownloadUpdateListener listener) { mOnDownloadUpdateListener = listener; } // 定义下载完成事件 private OnDownloadCompleteListener mOnDownloadCompleteListener; public interface OnDownloadCompleteListener { void onDownloadComplete(DownloadManagerAsync manager, Object result); } public void setOnDownloadCompleteListener( OnDownloadCompleteListener listener) { mOnDownloadCompleteListener = listener; } // 定义下载异常事件 private OnDownloadErrorListener mOnDownloadErrorListener; public interface OnDownloadErrorListener { void onDownloadError(DownloadManagerAsync manager, Exception e); } public void setOnDownloadErrorListener(OnDownloadErrorListener listener) { mOnDownloadErrorListener = listener; }}

调用上面的自定义的 Android 类库项目上点右键 -> Properties -> Java Build Path -> Projects -> Add 引用上面的类库 Main.java

代码

package com.webabcd.handler; import android.app.Activity; import android.os.Bundle; import android.widget.TextView; import webabcd.util.DownloadManagerAsync; public class Main extends Activity implements DownloadManagerAsync.OnDownloadCompleteListener, DownloadManagerAsync.OnDownloadUpdateListener, DownloadManagerAsync.OnDownloadErrorListener { TextView txt; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); DownloadManagerAsync manager = new DownloadManagerAsync(); manager.setOnDownloadCompleteListener(this); manager.setOnDownloadUpdateListener(this); manager.download("http://files.cnblogs.com/webabcd/Android.rar", "/sdcard/Android.rar"); txt = (TextView) this.findViewById(R.id.txt); txt.setText("开始下载"); } public void onDownloadComplete(DownloadManagerAsync manager, Object result) { txt.setText("下载完成"); } public void onDownloadUpdate(DownloadManagerAsync manager, int percent) { txt.setText("下载进度：" + String.valueOf(percent) + "%"); } public void onDownloadError(DownloadManagerAsync manager, Exception e) { txt.setText("下载出错"); } }

Android学习笔记总结

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Android学习笔记总结

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