Android开发--BroadcastReceiver2

上一篇文章介绍了在AndroidManifest.xml文件中定义过滤器的方法，这篇文章讲解使用java代码定义这些过滤器。

首先，介绍在xml文件中定义过滤器的弊端。如果开发者在xml文件中定义的不是系统级事件，正如上一篇文章中的那样，那么不管用户的应用程序是否关闭，Receiver程序始终处于运行（监听）状态，直到用户手机关闭。这样，就会对内存和手机电量造成极大的浪费，所以当用户不需要定义系统级事件时，可以使用简单的java代码实现过滤器的注册。

下面是具体的实现代码：

public class BroadcastReceiver01 extends Activity {
	private Button button;
	private Button button2;
	private Broadcast_receiver  brReceiver01;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_broadcast_receiver01);
		button=(Button)findViewById(R.id.button1);
		button2=(Button)findViewById(R.id.button2);
		button.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				brReceiver01=new Broadcast_receiver();
				IntentFilter intentFilter=new IntentFilter();
				intentFilter.addAction("BruceZhang");
			    registerReceiver(brReceiver01, intentFilter);
			    Intent intent=new Intent("BruceZhang");
//			    由于是并不是使用内置的Action，所以系统不会发出这个广播事件，仍然需要用户手动的去广播
			    sendBroadcast(intent);
			}
		});
		button2.setOnClickListener(new OnClickListener() {
			
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
			unregisterReceiver(brReceiver01);	
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.activity_broadcast_receiver01, menu);
		return true;
	}

}

public class Broadcast_receiver extends BroadcastReceiver {

	@Override
	public void onReceive(Context arg0, Intent arg1) {
		// TODO Auto-generated method stub
		Log.d("BruceZhang", "This is BroadcastReceiver!!!"+arg1.getAction());
		if(arg1.getAction()=="BruceZhang"){
			Log.d("BruceZhang", "---->This is BroadcastReceiver!!!");
		}
	}

}