Question

我正在尝试启动在后台运行的服务，该服务正在侦听ACTION_SCREEN_OFF，当它找到ACTION_SCREEN_OFF时，会启动我的活动。

我在某处读到了创建 BroadcastReceiver 所需的内容，因为将它放在清单XML中是行不通的。但是我不知道经过多次搜索后从哪里开始。

Answer 1

您无法在 AndroidManifest.xml 中声明ACTION_SCREEN_ON和ACTION_SCREEN_OFF。您只能在活动开始时捕获它们。

这是一个例子。

BroadcastReceiver ：

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();
    }

}

您可以通过从Service收听这些事件来解决您的问题。

Answer 2

我正在使用来自async categorySearch() { this.searchFlag = true; console.log(this.newSearch) console.log(this.tagLocation) let a =await bigQueryApi.querygo() console.log(a) }的回调来解决问题ScreenReceiver和onResume()。这些在onPause()之前被调用。

听取ACTION_SCREEN_OFF

2 个答案: