Android Bundle类

今天发现自己连Bundle类都没有搞清楚，于是花时间研究了一下。

依据google官方的文档（http://developer.android.com/reference/android/os/Bundle.html）

Bundle类是一个key-value对，“A mapping from String values to various Parcelable types.”

类继承关系：

java.lang.Object
     android.os.Bundle

Bundle类是一个final类：
public final class
Bundle
extends Objectimplements Parcelable Cloneable

两个activity之间的通讯能够通过bundle类来实现，做法就是：

（1）新建一个bundle类

Bundle mBundle = new Bundle(); 

mBundle.putString("Data", "data from TestBundle");

Intent intent = new Intent();  
intent.setClass(TestBundle.this, Target.class);  
intent.putExtras(mBundle);

android mainfest.xml例如以下：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.tencent.test"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".TestBundle"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
	<activity android:name=".Target"></activity>
    </application>
    <uses-sdk android:minSdkVersion="7" />
</manifest> 

类1：TestBundle类：

import android.app.Activity;  
import android.content.Intent;  
import android.os.Bundle;  
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class TestBundle extends Activity {  
	
	private Button button1;
	private OnClickListener cl; 
    public void onCreate(Bundle savedInstanceState) {  
    	super.onCreate(savedInstanceState);  
    	setContentView(R.layout.main);
        
    	button1 = (Button) findViewById(R.id.button1);
    	cl = new OnClickListener(){
    		@Override
    		public void onClick(View arg0) {
				// TODO Auto-generated method stub
				Intent intent = new Intent();  
				intent.setClass(TestBundle.this, Target.class);  
				Bundle mBundle = new Bundle();  
				mBundle.putString("Data", "data from TestBundle");//压入数据  
				intent.putExtras(mBundle);  
				startActivity(intent);
			}
        };
        button1.setOnClickListener(cl);
    }
}  

import android.app.Activity;  
import android.os.Bundle;  

public class Target extends Activity{  

    public void onCreate(Bundle savedInstanceState) {  
    	
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.target);  
        Bundle bundle = getIntent().getExtras();    //得到传过来的bundle
        String data = bundle.getString("Data");//读出数据  
        setTitle(data);  

    }  
}  

main.xml

<?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:text="@string/hello"
    />
<Button  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/button"
    android:id = "@+id/button1"
    /> 
</LinearLayout>

<?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:text="@string/target"
    />
</LinearLayout>

String.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="hello">Hello World, TestBundle!</string>
    <string name="app_name">測试Bundle使用方法</string>
    <string name="button">点击跳转</string>
    <string name="target">来到target activity</string>
</resources>

跳转结果：