在Android中解锁设备的屏幕时启动服务

Question

我希望在屏幕解锁时运行我的服务,并在屏幕锁定时停止它.我查看了这些答案并实施了它们.但是,当我锁定我的屏幕时,服务会根据需要停止,但是当我解锁屏幕时,它不会再次启动.

运行此服务的代码如下:

public class PhonePositionService extends Service {
@Override
    public void onCreate() {
    //ADDED CODE
    IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
    filter.addAction(Intent.ACTION_SCREEN_OFF);
    BroadcastReceiver mReceiver = new BootCompletedIntentReceiver();
    registerReceiver(mReceiver, filter);
    {...}
    }
@Override
    public int onStartCommand(Intent intent, int flags, int startId) {
    int icon = R.drawable.ic_stat_bright;
    startForeground(NOTIFICATION_ID, getCompatNotification(icon));
    if (backgroundThread != null) {
      backgroundThread.start();
    }
    return START_STICKY;
  }
}

在其他一些文件中,我的广播接收器代码如下:

public class BootCompletedIntentReceiver extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
   String action = intent.getAction();
   if(Intent.ACTION_SCREEN_ON.equals(action)) {
     // start the service
     Intent pushIntent = new Intent(context, PhonePositionService.class);
     context.startService(pushIntent);
   } else if(Intent.ACTION_SCREEN_OFF.equals(action)) {
     // stop the service
     Intent pushIntent = new Intent(context, PhonePositionService.class);
     context.stopService(pushIntent);
   }
  if ("android.intent.action.BOOT_COMPLETED".equals(intent.getAction())) {
    Intent pushIntent = new Intent(context, PhonePositionService.class);
    context.startService(pushIntent);
  }
 }
}

那么为什么当我解锁我的手机时,服务不会再次启动？

Answer 1

首先,在您拥有Admin Privilages之前,无法检测用户是否已解锁手机.您遇到的问题是因为您在屏幕关闭时停止PhonePositionService使用stopService():

public class BootCompletedIntentReceiver extends BroadcastReceiver {
 @Override
 public void onReceive(Context context, Intent intent) {
   String action = intent.getAction();
   if(Intent.ACTION_SCREEN_ON.equals(action)) {
     // start the service
     Intent pushIntent = new Intent(context, PhonePositionService.class);
     context.startService(pushIntent);
   } else if(Intent.ACTION_SCREEN_OFF.equals(action)) {
     // stop the service
     Intent pushIntent = new Intent(context, PhonePositionService.class);
     //This will stop the service
     context.stopService(pushIntent);
   }
  if ("android.intent.action.BOOT_COMPLETED".equals(intent.getAction())) {
    Intent pushIntent = new Intent(context, PhonePositionService.class);
    context.startService(pushIntent);
  }
 }
}

由于BroadcastReceiver未注册,因此会导致内存泄漏.

不鼓励将服务永久保持在前台运行,因为它可能导致(快速)电池排放.

我建议你找其他选择.但是,如果您的核心功能受到影响并且您仍想继续,则可以执行以下操作:

做BootCompletedIntentReceiver了作为内部类PhonePositionService.而不是启动和停止服务,您直接执行您的操作.

public class PhonePositionService extends Service {
   @Override
   public void onCreate() {
       //ADDED CODE
       IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
       filter.addAction(Intent.ACTION_SCREEN_OFF);
       BroadcastReceiver mReceiver = new BootCompletedIntentReceiver();
       registerReceiver(mReceiver, filter);
       ...
    }
    ...
    private class BootCompletedIntentReceiver extends BroadcastReceiver {
       @Override
       public void onReceive(Context context, Intent intent) {
         String action = intent.getAction();
         if(Intent.ACTION_SCREEN_ON.equals(action)) {
          //DO action for SCREEN_ON
         } else if(Intent.ACTION_SCREEN_OFF.equals(action)) {
          //Do action for SCREEN_OFF
         }

       }
   }
}