BroadcastReceiver广播

 

BroadcastReciever广播：
他采用了一种设计模式，熟称观察者模式。
意思：当我注册一个广播的时候，申明了标记Action
     当发送广播的时候，给传送的Intent设置了相同的标记Action
     一呼一答的模式。

注册广播实现方式（两种）:
一.在manifest.xml注册广播接收器
二.用代码动态实现广播接收器（一边在Activity的onResumu中实现）
先看第一种，实现如下：
1.创建广播接收器(MyReceiver )
public class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.i("MyReceiver", "ACTION = " + intent.getAction());
    }

}

2.在Manifest.xml中注册广播接收器
<receiver android:name=".MyReveiver">
           <intent-filter>
               <action android:name="com.zm.broad"></action>
           </intent-filter>
</receiver>

3.Activity中发送广播
final String ACTION = "com.zm.broad";
protected void onResume() {

        //发送广播
        Intent intent = new Intent();
        intent.setAction(ACTION);
        sendBroadcast(intent);

        super.onResume();
}
---------------------------------------------
第二种实现如下：
public class BroadcastActivity extends Activity {

    MyReceiver myReceiver;
    final String ACTION = "com.zm.broad";

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

//        Button button = (Button)findViewById(R.id.broadcast);
//        button.setOnClickListener(new OnClickListener(){
//
//          public void onClick(View v) {
//              Intent intent = new Intent();
//              intent.setAction(ACTION);
//              sendBroadcast(intent);
//          }
//
//        });


    }

    @Override
    protected void onResume() {

        myReceiver = new MyReceiver();
        IntentFilter filter = new IntentFilter();
        filter.addAction(ACTION);
        //注册
        registerReceiver(myReceiver, filter);

        //发送广播
        Intent intent = new Intent();
        intent.setAction(ACTION);
        sendBroadcast(intent);

        super.onResume();
    }

    @Override
    protected void onPause() {
        unregisterReceiver(myReceiver);
        super.onPause();
    }

    class MyReceiver extends BroadcastReceiver{
        @Override
        public void onReceive(Context context, Intent intent) {
            Log.i("MyReceiver", "ACTION = " + intent.getAction());
        }
    }

}