android之旅19 代码注册广播接收者

public void start(View v){
//ScreenReceiver继承BroadcastReceiver
ScreenReceiver receiver = new ScreenReceiver();
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_SCREEN_OFF);
filter.addAction(Intent.ACTION_SCREEN_ON);
registerReceiver(receiver, filter);
//解除注册中的receiver很明显应该和register中的同一个实例
unregisterReceiver(receiver);
}