Android学习笔记_30_常用控件使用

时间:2021-12-10 15:33:29

一、状态栏通知(Notification):

  如果需要查看消息,可以拖动状态栏到屏幕下方即可查看消息。发送消息的代码如下:

   public void sendNotice(View v){
int icon=android.R.drawable.stat_notify_chat;
//第一个参数为图标,第二个参数为标题,第三个为通知时间
Notification notification = new Notification(icon, "通知", System.currentTimeMillis());
notification.defaults = Notification.DEFAULT_SOUND;//发出默认声音
//打开通知时要启动的activity
Intent intent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:15901681812"));
PendingIntent pendingIntent = PendingIntent.getActivity(this, 1, intent, 0);
notification.setLatestEventInfo(this, "新消息", "时间到,请拨打电话", pendingIntent);
notification.flags = Notification.FLAG_AUTO_CANCEL;//自动取消
//获取通知管理器
NotificationManager manager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
manager.notify(11, notification);//第一个参数为自定义的通知唯一标识
}

二、对话框通知(Dialog Notification)

  当你的应用需要显示一个进度条或需要用户对信息进行确认时,可以使用对话框来完成。下面代码将打开一个如右图所示的对话框:

public void notifcation() {
new AlertDialog.Builder(this)
.setTitle("AlertDialog测试")
.setCancelable(false)
// 设置不能通过“后退”按钮关闭对话框
.setMessage("AlertDialog学习?")
.setPositiveButton("确认", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialoginterface, int i) {
Uri uri = Uri.parse("http://www.itcast.cn/");// 打开链接
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
})
.setNegativeButton("取消", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
}).show();// 显示对话框
}

三、创建带单选项列表的对话框

//下面代码将打开一个如右上图所示的选项列表对话框:
final String[] items = {"java", ".net", "php"};
new AlertDialog.Builder(SenderNotificationActivity.this).setTitle("选择语言")
.setItems(items, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int item) {
Toast.makeText(getApplicationContext(), items[item],
Toast.LENGTH_SHORT).show();
}
}).show();//显示对话框
//下面代码将打开一个如右下图所示的带单选框的列表对话框:
final String[] items = {"java", ".net", "php"};
new AlertDialog.Builder(SenderNotificationActivity.this).setTitle("选择语言")
.setSingleChoiceItems(items, 1, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int item) {
Toast.makeText(getApplicationContext(), items[item],
Toast.LENGTH_SHORT).show();
dialog.cancel();
}
}).show();//显示对话框
//setSingleChoiceItems()的第二个参数是设置默认选项,
选项索引从0开始,-1代表不选择任何选项。

四、创建带多选项列表的对话框

final String[] items = {"java", ".net", "php"};
new AlertDialog.Builder(SenderNotificationActivity.this).setCancelable(false)
.setTitle("选择语言")
.setMultiChoiceItems(items, new boolean[]{false,true,false}, new DialogInterface.OnMultiChoiceClickListener() {
@Override
public void onClick(DialogInterface dialog, int which, boolean isChecked) {
if(isChecked){
Toast.makeText(getApplicationContext(), items[which],
Toast.LENGTH_SHORT).show();
}
}
})
.setPositiveButton("确认",
new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialoginterface, int i){
dialoginterface.dismiss();
}
})
.show();//显示对话框

五、进度条

  使用代码ProgressDialog.show(ProgressDialogActivity.this, "请稍等", "数据正在加载中...", true);创建并显示一个进度对话框。

  调用setProgressStyle()方法设置进度对话框风格。有两种风格:

  ProgressDialog.STYLE_SPINNER 旋体进度条风格 (为默认风格)

  ProgressDialog.STYLE_HORIZONTAL 横向进度条风格

<!--在布局xml文件中添加进度条代码:-->
<ProgressBar
android:layout_width="fill_parent"
android:layout_height="20px"
style="?android:attr/progressBarStyleHorizontal"
android:id="@+id/downloadbar"/> <!--在代码中操作进度条:
ProgressBar.setMax(100);//设置最大刻度
ProgressBar.setProgress(0);//设置进度条的当前刻度,如果进度条的最大刻度为100,当前刻度为50,进度条将进行到一半。
-->
public class ProgressDialogActivity extends Activity {
private ProgressDialog progressDialog;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.menu);
//开始一条专门处理耗时工作的线程
new Thread(new Runnable(){
@Override
public void run() {
try {
Thread.sleep(5*1000);//假设这项工作需要5秒才能完成
progressDialog.dismiss();//关闭进程对话框
//runOnUiThread(finishDialog);//要求运行在UI线程
} catch (InterruptedException e) {}
}
}).start();
progressDialog = ProgressDialog.show(ProgressDialogActivity.this, "请稍等", "数据正在加载中...", true);
}
private Runnable finishDialog = new Runnable() {
@Override
public void run() {
progressDialog.dismiss();
}
};
}

六、单选框(RadioButton)

要完成单选框显示,我们需要使用到RadioGroup和RadioButton(单选框),RadioGroup用于对单选框进行分组,相同组内的单选框只有一个单选框能被选中。(例子代码请见下方备注栏)
RadioGroup.check(R.id.dotNet);将id名为dotNet的单选框设置成选中状态。
(RadioButton) findViewById(radioGroup.getCheckedRadioButtonId());//获取被选中的单选框。
RadioButton.getText();//获取单选框的值
调用setOnCheckedChangeListener()方法,处理单选框被选择事件,把RadioGroup.OnCheckedChangeListener实例作为参数传入

  界面设计:

界面设计:
<?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"
>
<RadioGroup android:id="@+id/radioGroup"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<RadioButton android:id="@+id/java"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="java" />
<RadioButton android:id="@+id/dotNet"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="dotNet" />
<RadioButton android:id="@+id/php"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="PHP" />
</RadioGroup>
</LinearLayout>

  处理程序

public void onCreate(Bundle savedInstanceState) {
RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radioGroup);
radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
public void onCheckedChanged(RadioGroup group, int checkedId) {
RadioButton radioButton = (RadioButton) findViewById(checkedId);
Log.i(TAG, String.valueOf(radioButton.getText()));
}
});
}

七、多选框(CheckBox)

  每个多选框都是独立的,可以通过迭代所有多选框,然后根据其状态是否被选中再获取其值。

  CheckBox.setChecked(true);//设置成选中状态。
  CheckBox.getText();//获取多选框的值
  调用setOnCheckedChangeListener()方法,处理多选框被选择事件,把CompoundButton.OnCheckedChangeListener实例作为参数传入。

界面设计:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="fill_parent">
<CheckBox android:id="@+id/checkboxjava"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="java" />
<CheckBox android:id="@+id/checkboxdotNet"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="dotNet" />
<CheckBox android:id="@+id/checkboxphp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="PHP" /> <Button android:id="@+id/checkboxButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="获取值" />
</LinearLayout>

代码处理

public class CheckBoxActivity extends Activity {
private static final String TAG = "CheckBoxActivity";
private List<CheckBox> checkboxs = new ArrayList<CheckBox>(); @Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
checkboxs.add((CheckBox) findViewById(R.id.checkboxdotNet));
checkboxs.add((CheckBox) findViewById(R.id.checkboxjava));
checkboxs.add((CheckBox) findViewById(R.id.checkboxphp));
checkboxs.get(1).setChecked(true);// 设置成选中状态
for (CheckBox box : checkboxs) {
box.setOnCheckedChangeListener(listener);
}
Button button = (Button) findViewById(R.id.checkboxButton);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
List<String> values = new ArrayList<String>();
for (CheckBox box : checkboxs) {
if (box.isChecked()) {
values.add(box.getText().toString());
}
}
Toast.makeText(CheckBoxActivity.this, values.toString(), 1).show();
}
});
} private CompoundButton.OnCheckedChangeListener listener = new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
CheckBox checkBox = (CheckBox) buttonView;
Log.i(TAG,"isChecked=" + isChecked + ",value=" + checkBox.getText());// 输出单选框的值
}
};
}

八、下拉列表框(Spinner)

  Spinner.getItemAtPosition(Spinner.getSelectedItemPosition());//获取下拉列表框的值,
//调用setOnItemSelectedListener()方法,处理下拉列表框被选择事件,把AdapterView.OnItemSelectedListener实例作为参数传入。

  1、Spinner的界面设计:

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

代码处理:

public class SpinnerActivity extends Activity {
private static final String TAG = "SpinnerActivity"; @Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.spinner);
// 第二个参数为下拉列表框每一项的界面样式,该界面样式由Android系统提供,当然您也可以自定义
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
adapter.add("java");
adapter.add("dotNet");
adapter.add("php");
Spinner spinner = (Spinner) findViewById(R.id.spinner);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view,
int position, long id) {
Spinner spinner = (Spinner) adapterView;
String itemContent = (String) adapterView.getItemAtPosition(position);
Log.i(TAG, itemContent+" : "+spinner);
} @Override
public void onNothingSelected(AdapterView<?> view) {
Log.i(TAG, view.getClass().getName());
}
});
}
}

  很多时候显示在下拉列表框的值并不是希望得到的值,如果要做一个联系人下拉列表框,列表框列出的是联系人的姓名,因为姓名有可能相同,所以我们希望得到的值应该为该联系人的id,要实现这种需求我们需要自定义Adapter,当然自定义Adapter需要我们编写一小段代码,如果我们不想编写Adapter,又能实现我们的需求,那是最好不过的了。通过观察ArrayAdapter中getView(int position, View convertView, ViewGroup parent)的内部代码发现,如果为ArrayAdapter指定的实际泛型参数类型没有实现CharSequence(字符串)接口,将会调用该类型对象的toString()向下拉列表框输出显示值。利用这个特点我们可以重写javaBean的toString()向下拉列表框提供显示值。

  2、通过有没有实现CharSequence接口,来改变下拉列表框的显示值

public class SpinnerActivity extends Activity {
private static final String TAG = "SpinnerActivity";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.spinner);
ArrayAdapter<Person> adapter = new ArrayAdapter<Person>(this, android.R.layout.simple_spinner_item);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
adapter.add(new Person(12, "李明"));
adapter.add(new Person(100, "李明"));
adapter.add(new Person(62, "张天"));
Spinner spinner = (Spinner) findViewById(R.id.spinner);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int position, long id) {
Spinner spinner = (Spinner)adapterView;
Person person = (Person)adapterView.getItemAtPosition(position);
}
@Override
public void onNothingSelected(AdapterView<?> view) {
Log.i(TAG, view.getClass().getName());
}
});
}
}

Person.java

Person.java:
public class Person {
private Integer id;
private String name; public Person(Integer id, String name) {
this.id = id;
this.name = name;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
}

  3、自定义下拉列表框样式:

    3.1下拉列表框每一项的界面样式:stylespinner.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/contentTextView"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#F4FDFF"
/>

    3.2代码处理

public class SpinnerActivity extends Activity {
private static final String TAG = "SpinnerActivity";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.spinner);
//第二个参数为layout文件在R文件的id,第三个参数为TextView在layout文件的id
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, R.layout.stylespinner, R.id.contentTextView);
adapter.add("java");
adapter.add("dotNet");
adapter.add("php");
Spinner spinner = (Spinner) findViewById(R.id.spinner);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int position, long id) {
Spinner spinner = (Spinner)adapterView;
String itemContent = (String)adapterView.getItemAtPosition(position);
}
@Override
public void onNothingSelected(AdapterView<?> view) {
Log.i(TAG, view.getClass().getName());
}
});
}
}

九、拖动条(SeekBar)

  SeekBar.getProgress()获取拖动条当前值

  调用setOnSeekBarChangeListener()方法,处理拖动条值变化事件,把SeekBar.OnSeekBarChangeListener实例作为参数传入。

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" > <SeekBar
android:id="@+id/seekBar"
android:layout_width="fill_parent"
android:layout_height="wrap_content" /> <Button
android:id="@+id/seekBarButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="获取值" /> </LinearLayout>
public class MainActivity extends Activity {
private SeekBar seekBar; @Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.seekbar);
seekBar = (SeekBar) findViewById(R.id.seekBar);
seekBar.setMax(100);// 设置最大刻度
seekBar.setProgress(30);// 设置当前刻度
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromTouch) {
Log.v("onProgressChanged()", String.valueOf(progress) + ", "
+ String.valueOf(fromTouch));
} @Override
public void onStartTrackingTouch(SeekBar seekBar) {// 开始拖动
Log.v("onStartTrackingTouch()",
String.valueOf(seekBar.getProgress()));
} @Override
public void onStopTrackingTouch(SeekBar seekBar) {// 结束拖动
Log.v("onStopTrackingTouch()",
String.valueOf(seekBar.getProgress()));
}
}); Button button = (Button) this.findViewById(R.id.seekBarButton);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(MainActivity.this,
String.valueOf(seekBar.getProgress()), 1).show();
}
});
}
}

十、菜单(Menu)

  1、重写Activity的onCreateOptionsMenu(Menu menu)方法,该方法用于创建选项菜单,在用户按下手机的“Menu”按钮时就会显示创建好的菜单,在onCreateOptionsMenu(Menu menu)方法内部可以调用Menu.add()方法实现菜单的添加。

  2、重写Activity的onMenuItemSelected()方法,该方法用于处理菜单被选择事件。通过手机上提供的“MENU”按钮可以打开菜单,如果希望通过代码打开菜单,可以调用Activity的openOptionsMenu()方法。

public class MenuActivity extends Activity {
private static final String TAG = "MenuActivity";
private static final int MENU_ADD = Menu.FIRST;
private static final int MENU_UPDATE = Menu.FIRST + 1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.menu);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
menu.add(Menu.NONE, MENU_ADD, Menu.NONE, "添加");
menu.add(Menu.NONE, MENU_UPDATE, Menu.NONE, "更新");
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
switch (item.getItemId()) {
case MENU_ADD:
Log.i(TAG, "add was selected");
return true;
case MENU_UPDATE:
Log.i(TAG, "update was selected");
return true;
default:
return super.onMenuItemSelected(featureId, item);
}
}
}

十一、自动完成文本框(AutoCompleteTextView)

  AutoCompleteTextView和EditText组件类似,都可以输入文本。但AutoCompleteTextView组件可以和一个字符串数组或List对

绑定,当用户输入两个及以上字符时,系统将在AutoCompleteTextView组件下方列出字符串数组中所有以输入字符开头的字符串,这一点和www.google.com的搜索框非常相似,当输入某一个要查找的字符串时,google搜索框就会列出以这个字符串开头的最热门的搜索字符串列表。

<AutoCompleteTextView

   android:layout_width="fill_parent“  android:layout_height="wrap_content“

  <!-- completionThreshold 指定至少输入几个字符后才会出现自动提示功能-->
android:completionThreshold="1“ android:id="@+id/name" />
public void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);
setContentView(R.layout.main);
String[] names = {"abcd", "wers", "123a", "123s" , "sfsf", "sss", "abc", "acc"};
AutoCompleteTextView nameText = (AutoCompleteTextView)this.findViewById(R.id.name);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, names);
nameText.setAdapter(adapter); }

  除了AutoCompleteTextView控件外,我们还可以使用MultiAutoCompleteTextView控件来完成连续输入的功能。也就是说,当输入完一个字符串后,在该字符串后面输入一个逗号(,),在逗号前后可以有任意多个空格,然后再输入一个字符串,仍然会显示自动提示列表。

  使用MultiAutoCompleteTextView时,需要为它的setTokenizer方法指定MultiAutoCompleteTextView.CommaTokenizer类对象实例,该对象表示采用逗号作为输入多个字符串的分隔符。

< MultiAutoCompleteTextView

android:layout_width="fill_parent“  android:layout_height="wrap_content“

<!– completionThreshold 指定至少输入几个字符后才会出现自动提示功能à

android:completionThreshold="1“

android:id="@+id/name" />

public void onCreate(Bundle savedInstanceState) {  super.onCreate(savedInstanceState);

setContentView(R.layout.main);

String[] names = {"abcd", "wers", "123a", "123s" , "sfsf", "sss", "abc", "acc"};
     MultiAutoCompleteTextView nameText = (MultiAutoCompleteTextView)this.findViewById(R.id.name);

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line,    names);

nameText.setAdapter(adapter);

nameText.setTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());}