//第一種方法

需要清單文件
<uses-permission Android:name="android.permission.GET_TASKS" />

public static boolean isApplicationBroughtToBackground(final Context context) {
    //創(chuàng)建activity管理對(duì)象
   ActivityManager activityManager = (ActivityManager) context.getSystemService(ACTIVITY_SERVICE);

    //取出RunningTask棧
   List<ActivityManager.RunningTaskInfo> list =activityManager.getRunningTasks(1);
    //判斷是否為空
    if (!list.isEmpty()){
        //取出運(yùn)行在棧頂?shù)娜蝿?wù)進(jìn)程
        ComponentName componentName = list.get(0).topActivity;
        //判斷任務(wù)進(jìn)程的包名是否和想要判斷的程序包名相同
        if (componentName.getPackageName().equals(context.getPackageName())){
            //相同則說(shuō)明你該程序運(yùn)行在前臺(tái)，則返回ture
            return true;
        }
    }
    //否則返回false
    return false;
}

//第二種方法

public static boolean isBackground(Context context) {
    //創(chuàng)建activity管理對(duì)象
    ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    //獲取當(dāng)前正在運(yùn)行的進(jìn)程的list
    List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
    //找到需要判斷的程序的進(jìn)程
    //從appProcesses把進(jìn)程一個(gè)一個(gè)取出
    for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {

        //判斷包名來(lái)找到自己的程序
        if (appProcess.processName.equals(context.getPackageName())) {

            /*
            * IMPORTANCE_BACKGROUND   后臺(tái)
        IMPORTANCE_EMPTY    空
        IMPORTANCE_FOREGROUND   前臺(tái)
        IMPORTANCE_PERCEPTIBLE  //后臺(tái)，但是可以和用戶進(jìn)行交互（一般音樂(lè)播放器）
       IMPORTANCE_SERVICE    服務(wù)
        IMPORTANCE_VISIBLE    可見(jiàn)
            * */

            //判斷importance屬性是否為IMPORTANCE_BACKGROUND？
            if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_BACKGROUND) {
                Log.i("后臺(tái)", appProcess.processName);
                return true;
            }else{
                Log.i("前臺(tái)", appProcess.processName);
                return false;
            }
        }
    }
    return false;
}