//在进程中去寻找当前APP的信息，判断是否在前台运行

private boolean isAppOnForeground() {

ActivityManager activityManager =(ActivityManager) getApplicationContext().getSystemService(

   Context.ACTIVITY_SERVICE);

String packageName =getApplicationContext().getPackageName();

List<RunningAppProcessInfo>appProcesses = activityManager.getRunningAppProcesses();

if (appProcesses == null)

return false;

for (RunningAppProcessInfo appProcess : appProcesses) {

if (appProcess.processName.equals(packageName)

       && appProcess.importance == RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {

   return true;

}

}

return false;

}