在service中检查Activity是否运行

public boolean isForeground(String myPackage){
ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
 List< ActivityManager.RunningTaskInfo > runningTaskInfo = manager.getRunningTasks(1);

     ComponentName componentInfo = runningTaskInfo.get(0).topActivity;
   if(componentInfo.getPackageName().equals(myPackage)) return true;
return false;
}

增加permission：

<uses-permission android:name="android.permission.GET_TASKS" />