Broadcast 广播发送及接收

Broadcast功能在于可以向手机中的其他程序发送消息，实现程序间互相通信。比如Android系统在启动，闹钟，来电等一些情况下，会广播一些消息给所有的接收者，其他程序在收到信息后可以做进一步动作。
今天的DEMO介绍一下，程序有两个Class。一个是主Activity,主要做界面显示，发送广播，另一个是广播接收器，用于收到主Activity广播后执行相应动作。
布局XML代码就不贴了，就一按钮。
main.java:

package com.pocketdigi.Broadcast; 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 main extends Activity {    /** Called when the activity is first created. */static final String action1="Broadcast_action1";    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        Button b1=(Button)findViewById(R.id.b1);        b1.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View v) {// TODO Auto-generated method stubIntent it = new Intent(action1);sendBroadcast(it); //点击按钮后广播一个Intent,内容是action1//action1这个字符串，相当于一个ID，接收广播识别用的}         }        );    }}

接收器Broadcastreceiver.java:

package com.pocketdigi.Broadcast; import android.content.BroadcastReceiver;import android.content.Context;import android.content.Intent;import android.widget.Toast; public class Broadcastreceiver extends BroadcastReceiver { @Overridepublic void onReceive(Context context, Intent intent) {//接收到后执行以下内容//这里不用考虑接收到的是否就是我们要的广播//因为这一步已经放在AndroidManifest.xml里设置了 Toast.makeText(context, "成功接收广播", Toast.LENGTH_LONG).show();  } }

在AndroidManifest.xml里注册一下接收器：

<receiver android:name=".Broadcastreceiver">  <intent-filter>   <action android:name="Broadcast_action1" />  </intent-filter> </receiver>

这段代码的意思是，如果广播的action是”Broadcast_action1″,就通知Broadcastreceiver这个接收器，代码放在application标签内

在代码中注册receiver

    private BroadcastReceiver receiver = new BroadcastReceiver() {        @Override        public void onReceive(Context context, Intent intent) {            // TODO Auto-generated method stub            if (MyLayout.ACTION_MOUSE_PRESSED.equals(intent.getAction())) {                mMouseImageView.setImageResource(R.drawable.image_first_0);            } else if (MyLayout.ACTION_MOUSE_RELEASED.equals(intent.getAction())) {                mMouseImageView.setImageResource(R.drawable.image_first_1);            }else if (MyLayout.ACTION_MOUSE_BAD.equals(intent.getAction())) {                //do nothing here                            }        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        // TODO Auto-generated method stub        super.onCreate(savedInstanceState);        setContentView(R.layout.rcthird_layout);        init();    }    private void init() {        view = new MyLayout(this, null);        view.setBackgroundColor(R.color.third_background);        mButtonNextStep = (Button) this.findViewById(R.id.third_next_button);        mButtonNextStep.setOnClickListener(this);        mMouseImageView = (ImageView) this.findViewById(R.id.third_mouse);        mIntentFilter = new IntentFilter();        mIntentFilter.addAction(MyLayout.ACTION_MOUSE_PRESSED);        mIntentFilter.addAction(MyLayout.ACTION_MOUSE_RELEASED);        mIntentFilter.addAction(MyLayout.ACTION_MOUSE_BAD);        registerReceiver(receiver, mIntentFilter);    }