在Android中传递数据的方法非常多,本次介绍4中比较常用的数据传递方法:
1.通过Intent传递数据
2.通过静态变量(static)传递数据
3.通过剪贴板(Clipboard)传递数据
4.通过全局对象传递数据
在TransmitDataActivity.java中
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package mobile.android.transmit.data;
public class TransmitDataActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super .onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1=(Button)findViewById(R.id.button1);
Button button2=(Button)findViewById(R.id.button2);
Button button3=(Button)findViewById(R.id.button3);
Button button4=(Button)findViewById(R.id.button4);
button1.setOnClickListener( new ButtonListenner());
button2.setOnClickListener( new ButtonListenner());
button3.setOnClickListener( new ButtonListenner());
button4.setOnClickListener( new ButtonListenner());
}
class ButtonListenner implements OnClickListener{
@SuppressLint ( "NewApi" )
@Override
public void onClick(View view) {
Intent intent= null ;
switch (view.getId()) {
case R.id.button1:
intent= new Intent(TransmitDataActivity. this ,MyActivity1. class );
//保存String类型的值
intent.putExtra( "intent_string" , "通过Intent传递的字符串" );
//保存integer类型的值
intent.putExtra( "intent_integer" , 300 );
Data data= new Data();
data.id= 1000 ;
data.name= "Android" ;
//保存可序列化的对象
intent.putExtra( "intent_object" , data);
//显示用于接收数据的Activity
startActivity(intent);
break ;
case R.id.button2:
intent= new Intent();
intent.setClass(TransmitDataActivity. this , MyActivity2. class );
//下面的代码为MyActivity2中放入三个静态变量赋值
MyActivity2.id= 3000 ;
MyActivity2.name= "保时捷" ;
MyActivity2.data= new Data();
MyActivity2.data.id= 5555 ;
MyActivity2.name= "Android" ;
startActivity(intent);
break ;
case R.id.button3:
intent= new Intent(TransmitDataActivity. this ,MyActivity3. class );
//获取剪贴板对象(ClipboardManager)
ClipboardManager clipboard=(ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
//创建Data对象
Data clipboardData= new Data();
//设置Data对象中字段的值
clipboardData.id= 6666 ;
clipboardData.name= "通过Clipboard传递的数据" ;
//创建字节数组输出流对象,用于将Data对象转换为字节流
ByteArrayOutputStream baos= new ByteArrayOutputStream();
//用于保存Data对象生成Base64格式的字符串
String base64Str= "" ;
try {
ObjectOutputStream oos= new ObjectOutputStream(baos);
//将Data对象写入对象输出流
oos.writeObject(clipboardData);
//将字节流进行Base64编码
base64Str=Base64.encodeToString(baos.toByteArray(), Base64.DEFAULT);
oos.close();
} catch (IOException e) {
e.printStackTrace();
}
//获取存储文本数据的剪贴板数据对象(ClipData)
ClipData clipData=ClipData.newPlainText( "data" , base64Str);
//设置主剪贴板
clipboard.setPrimaryClip(clipData);
//显示Myactivity3窗口
startActivity(intent);
break ;
case R.id.button4:
//获取MyApp对象
MyApp myApp=(MyApp) getApplicationContext();
myApp.country= "美国" ;
myApp.data.id= 1234 ;
myApp.data.name= "飞碟" ;
intent= new Intent(TransmitDataActivity. this ,MyActivity4. class );
startActivity(intent);
break ;
default :
break ;
}
}
}
}
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Data类:这个类是可序列化的,也就是实现了java.io.Serializable接口的类。
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package mobile.android.transmit.data;
import java.io.Serializable;
public class Data implements Serializable{
public int id;
public String name;
}
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在Myactivity1.java中:package mobile.android.transmit.data;
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public class MyActivity1 extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super .onCreate(savedInstanceState);
setContentView(R.layout.myactivity);
TextView textView=(TextView)findViewById(R.id.textview);
//获得String类型的值
String intentString=getIntent().getStringExtra( "intent_string" );
//获得Integer类型的值
int intentInteger=getIntent().getExtras().getInt( "intent_integer" );
//获得Data类型的值
Data data=(Data) getIntent().getExtras().get( "intent_object" );
StringBuffer sb= new StringBuffer();
sb.append( "Intent_string:" );
sb.append(intentString);
sb.append( "\n" );
sb.append( "intent_integer:" );
sb.append(intentInteger);
sb.append( "\n" );
sb.append( "data.id:" );
sb.append(data.id);
sb.append( "\n" );
sb.append( "data.name:" );
sb.append(data.name);
sb.append( "\n" );
//在屏幕上输出传递过来的值
textView.setText(sb.toString());
}
}
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在Myactivity2.java中:
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package mobile.android.transmit.data;
public class MyActivity2 extends Activity{
public static String name;
public static int id;
public static Data data;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super .onCreate(savedInstanceState);
setContentView(R.layout.myactivity);
TextView textView=(TextView)findViewById(R.id.textview);
StringBuffer sb= new StringBuffer();
sb.append( "name:" );
sb.append(name);
sb.append( "\n" );
sb.append( "id:" );
sb.append(id);
sb.append( "\n" );
sb.append( "data.id:" );
sb.append(data.id);
sb.append( "\n" );
sb.append( "data.name:" );
sb.append(data.name);
sb.append( "\n" );
textView.setText(sb.toString());
}
}
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在Myactivity3中:
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package mobile.android.transmit.data;
public class MyActivity3 extends Activity{
@SuppressLint ( "NewApi" )
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super .onCreate(savedInstanceState);
setContentView(R.layout.myactivity);
TextView textView=(TextView)findViewById(R.id.textview);
//获取剪贴板对象
ClipboardManager clipboardManager=(ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
//从剪贴板中获取Base64编码字符串
String base64Str=clipboardManager.getPrimaryClip().getItemAt( 0 ).getText().toString();
//将Base64编码字符串编码成字节数组
byte [] buffer=Base64.decode(base64Str, Base64.DEFAULT);
ByteArrayInputStream bais= new ByteArrayInputStream(buffer);
try {
ObjectInputStream ois= new ObjectInputStream(bais);
//将字节流还原成Data对象
Data data=(Data) ois.readObject();
//将Base64编码原文和Data对象字段值显示在TextView控件中
textView.setText(base64Str+ "\n\ndata.id:" +data.id+ "\ndata.name:" +data.name);
} catch (Exception e) {
e.printStackTrace();
}
}
}
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在Myactivity4.java中:
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package mobile.android.transmit.data;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class MyActivity4 extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super .onCreate(savedInstanceState);
setContentView(R.layout.myactivity);
TextView textView=(TextView) findViewById(R.id.textview);
MyApp myApp=(MyApp) getApplicationContext();
textView.setText( "MyApp.country:" +myApp.country+ "\nMyApp.data.id:" +myApp.data.id+ "\nMyApp.data.name:" +myApp.data.name);
}
}
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关于在不同Activity之间传递数据的四种常用方法小编就给大家介绍这么多,希望对大家有所帮助!