android屏幕加解锁事件广播的监听
想在程序中监听屏幕SCREEN_ON和SCREEN_OFF这两个action,实现屏幕锁定状态的监听，从而实现自己的相应功能。比较奇怪的是这两个action只能通过代码的形式注册才能被监听到，在AndroidManifest.xml中注册根本监听不到。去网上查了一下，原来是PowerManager那边在发这个广播的时候做了限制，限制只有register到代码中的receiver才能接收。特此记录！
public class ScreenActionReceiver extends BroadcastReceiver {private String TAG = "ScreenActionReceiver";private boolean isRegisterReceiver = false;@Overridepublic void onReceive(Context context, Intent intent) {String action = intent.getAction();if (action.equals(Intent.ACTION_SCREEN_ON)) {Logcat.d(TAG, "屏幕解锁广播...");} else if (action.equals(Intent.ACTION_SCREEN_OFF)) {Logcat.d(TAG, "屏幕加锁广播...");}}public void registerScreenActionReceiver(Context mContext) {if (!isRegisterReceiver) {isRegisterReceiver = true;IntentFilter filter = new IntentFilter();filter.addAction(Intent.ACTION_SCREEN_OFF);filter.addAction(Intent.ACTION_SCREEN_ON);Logcat.d(TAG, "注册屏幕解锁、加锁广播接收者...");mContext.registerReceiver(ScreenActionReceiver.this, filter);}}public void unRegisterScreenActionReceiver(Context mContext) {if (isRegisterReceiver) {isRegisterReceiver = false;Logcat.d(TAG, "注销屏幕解锁、加锁广播接收者...");mContext.unregisterReceiver(ScreenActionReceiver.this);}}}