当屏幕/ CPU关闭时，不会调用Broadcast Receiver onReceive方法

Question

我正在研究一个应用程序，它会通知我（通过播放铃声）电池电量已达到特定级别。级别是可配置的。为此，我创建了一个启动服务的活动，该服务又将一个接收器注册为ACTION_BATTERY_CHANGED。 MyActivity - >为MyService - > MyBrodcastReceiver [ACTION_BATTERY_CHANGED] - >的onReceive（） - >如果（电池电量< = myvalue的） - >播放铃声

一切工作正常，只要屏幕上，但一旦手机被锁定屏幕熄灭或cpu睡眠广播接收器的onReceive方法不会被调用，当我再次解锁手机时，一切正常。我用日志记录验证了这一点

是否仅当手机屏幕打开时才会调用ACTION_BATTERY_CHANGED的onReceive方法，并在电话睡眠时停止？

我甚至在的onReceive方法使用唤醒锁尝试，但没有奏效

import android.app.Service; 
import android.content.Intent; 
import android.content.IntentFilter; 
import android.os.IBinder; 
import android.util.Log; 


public class BatteryMeterService extends Service { 

    private BatteryStatusReceiver batteryStatusReceiver; 

    @Override 
    public IBinder onBind(Intent intent) { 
     return null; 
    } 

    @Override 
    public void onCreate() { 
     super.onCreate(); 
     IntentFilter intentFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED); 
     batteryStatusReceiver = new BatteryStatusReceiver(null); 
     registerReceiver(batteryStatusReceiver, intentFilter);  
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     unregisterReceiver(batteryStatusReceiver); 
    } 

} 


import android.app.Activity; 
import android.content.BroadcastReceiver; 
import android.content.Context; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.os.BatteryManager; 
import android.os.PowerManager; 
import android.preference.PreferenceManager; 
import android.provider.Settings; 
import android.util.Log; 
import android.widget.TextView; 

import com.amol.bm.BatteryMeterUtility.NotificationInfo; 

public class BatteryStatusReceiver extends BroadcastReceiver { 


    private BatteryMeterUtility batteryMeterUtility; 

    public BatteryStatusReceiver() { 
     super(); 
    } 

    @Override 
    public void onReceive(Context context, Intent intent) { 


     int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1); 
     int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1); 
     float fPct = (level/(float)scale) * 100; 
     int levelPct = (int)fPct; 

     boolean prefAlertLowBattery = sharedPrefs.getBoolean("prefAlertLowBattery", true); 
     if(prefAlertLowBattery) { 
       String prefAlertLowBatteryValue = sharedPrefs.getString("prefAlertLowBatteryValue", "20"); 
       int lowBatteryValue = Integer.parseInt(prefAlertLowBatteryValue); 
       if(levelPct <= lowBatteryValue && iStatus != BatteryManager.BATTERY_STATUS_CHARGING) { 
       notificationInfo.icon = R.drawable.low_battery; 
       PowerManager powerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE); 
       PowerManager.WakeLock wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "BM WakeLook"); 
       wakeLock.acquire(); 
       batteryMeterUtility.playAlertRingtone(alertRingtone); 
       wakeLock.release(); 
       } 
     } 
    } 

} 

Answer 1

最后我用Alarm Manager与RTC_WAKEUP来解决这个问题。 http://developer.android.com/reference/android/app/AlarmManager.html

Answer 2

你应该给WAKE_LOCK权限[我与ICS（4.0.4）测试]你服务在后台运行，即使手机处于空闲或关机状态，您的服务仍可继续运行。希望你知道，如果不清楚