android - 监听 ACTION_SCREEN_OFF

Question

我正在尝试启动一个在后台运行的服务，该服务正在侦听ACTION_SCREEN_OFF，当它找到时ACTION_SCREEN_OFF，开始我的活动。

我在某处读到您需要创建一个BroadcastReceiver，因为将它放在清单 XML 中是行不通的。但是，经过大量搜索，我不知道从哪里开始。

Answer 1

您不能在AndroidManifest.xmlACTION_SCREEN_ON中声明和。您只能在活动运行时捕捉它们。ACTION_SCREEN_OFF

这是一个例子。

广播接收器：

public class ScreenReceiver extends BroadcastReceiver {

    public static boolean wasScreenOn = true;

    @Override
    public void onReceive(final Context context, final Intent intent) {
        if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
            // do whatever you need to do here
            wasScreenOn = false;
        } else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
            // and do whatever you need to do here
            wasScreenOn = true;
        }
    }

}

活动：_

public class ExampleActivity extends Activity {

    private BroadcastReceiver mReceiver = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // initialize receiver
        final IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        mReceiver = new ScreenReceiver();
        registerReceiver(mReceiver, filter);
        // your code
    }

    @Override
    protected void onPause() {
        // when the screen is about to turn off
        if (ScreenReceiver.wasScreenOn) {
            // this is the case when onPause() is called by the system due to a screen state change
            Log.e("MYAPP", "SCREEN TURNED OFF");
        } else {
            // this is when onPause() is called when the screen state has not changed
        }
        super.onPause();
    }

    @Override
    protected void onResume() {
        super.onResume();
        // only when screen turns on
        if (!ScreenReceiver.wasScreenOn) {
            // this is when onResume() is called due to a screen state change
            Log.e("MYAPP", "SCREEN TURNED ON");
        } else {
            // this is when onResume() is called when the screen state has not changed
        }
    }

    @Override
    protected void onDestroy() {
        if (mReceiver != null) {
            unregisterReceiver(mReceiver);
            mReceiver = null;
        }
        super.onDestroy();
    }

}

您可能可以通过收听来自Service.

Answer 2

我正在使用回调ScreenReceiver来解决问题onResume()，并且onPause(). 这些在BroadcastReceiver.onReceive().