当应用程序处于前台或活动状态时广播接收器不工作

Question

我正在构建有关电池指示器的应用程序，我正在使用此 post 中的代码。

Getting battery status even when the application is closed

当应用程序关闭时它工作正常，但是当应用程序处于活动状态或在前台时它不工作或没有发送任何广播。

这是主要的activity 从我开始服务

public class Main extends Activity {

private MyService service;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    if (service == null) {

        Intent i = new Intent(this, MyService.class);
        startService(i);
    }

    finish();
}

}

以下是服务代码。

public class MyService extends Service{

@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    Log.d("MyService", "onStartCommand");
    // do not receive all available system information (it is a filter!)
    final IntentFilter battChangeFilter = new IntentFilter(
            Intent.ACTION_BATTERY_CHANGED);
    // register our receiver
    this.registerReceiver(this.batteryChangeReceiver, battChangeFilter);
    return super.onStartCommand(intent, flags, startId);
}
private final BroadcastReceiver batteryChangeReceiver = new BroadcastReceiver() {

    @Override
    public void onReceive(final Context context, final Intent intent) {
        checkBatteryLevel(intent);
    }
};

private void checkBatteryLevel(Intent batteryChangeIntent) {
    // some calculations
    final int currLevel = batteryChangeIntent.getIntExtra(
            BatteryManager.EXTRA_LEVEL, -1);
    final int maxLevel = batteryChangeIntent.getIntExtra(
            BatteryManager.EXTRA_SCALE, -1);
    final int percentage = (int) Math.round((currLevel * 100.0) / maxLevel);

    if(percentage==100)
    {
        Intent intent = new Intent(getBaseContext(), Last.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        getApplication().startActivity(intent);

    }
    // do not forget to unregister
    unregisterReceiver(batteryChangeReceiver);
} }

并且在关注 activity 开始时我没有收到任何广播。

public class Last extends Activity {
Button btnCancel;
Uri notification;
Ringtone r;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_last);

    notification = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE);
    r = RingtoneManager.getRingtone(getApplicationContext(), notification);
    r.play();


     btnCancel = (Button) findViewById(R.id.stopsound);

     btnCancel.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub

             r.stop();
        }
    });

}  }

Answer 1

据我了解，当您第一次启动应用程序时，您什么也看不到，只是启动了服务并注册了一个广播接收器。当电池电量将被更改时，方法 checkBatteryLevel() 正在调用并且广播接收器将被注销。因此，您从未收到过新的电池电量变化。

当应用程序处于前台或活动状态时广播接收器不工作

Broadcast receiver is not working when app on foreground or active

android

broadcastreceiver