android - 监听 ACTION_SCREEN_OFF

Question

我正在尝试启动一个在后台运行的服务，该服务正在监听 ACTION_SCREEN_OFF，当它找到 ACTION_SCREEN_OFF 时，启动我的 Activity 。

我在某处读到您需要创建一个BroadcastReceiver，因为将它放在 list 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.xml 中声明 ACTION_SCREEN_ON 和 ACTION_SCREEN_OFF。您只能在 Activity 运行时捕捉它们。

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;
        }
    }

}

Activity :

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();
    }

}

您可能可以通过从 Service 监听这些事件来解决您的问题。