Android判斷App是否位於前臺

    /**
     * 自動根據參數選擇判斷前後臺的方法
     *
     * @param context     上下文參數
     * @return
     */
    public static boolean isForeground(Context context) {
        boolean runningTask = getRunningTask(context, context.getPackageName());
        boolean runningAppProcesses = getRunningAppProcesses(context, context.getPackageName());
        return runningTask && runningAppProcesses;
        }
        
 /**
     * 方法1：通過getRunningTasks判斷App是否位於前臺，此方法在5.0以上失效
     *
     * @param context     上下文參數
     * @param packageName 需要檢查是否位於棧頂的App的包名
     * @return
     */
    public static boolean getRunningTask(Context context, String packageName) {
        try{
            ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
            List<ActivityManager.RunningTaskInfo> runningTasks = am.getRunningTasks(1);
            if (runningTasks != null && runningTasks.size() > 0) {
                ComponentName cn = runningTasks.get(0).topActivity;
                return !TextUtils.isEmpty(packageName) && packageName.equals(cn.getPackageName());
            }
        }catch (Exception e){
            e.printStackTrace();
        }
        return false;
    }


    /**
     * 方法2：通過getRunningAppProcesses的IMPORTANCE_FOREGROUND屬性判斷是否位於前臺，當service需要常駐後臺時候，此方法失效,
     * 在小米 Note上此方法無效，在Nexus上正常
     *
     * @param context     上下文參數
     * @param packageName 需要檢查是否位於棧頂的App的包名
     * @return
     */
    public static boolean getRunningAppProcesses(Context context, String packageName) {
        ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
        if (appProcesses == null) {
            return false;
        }
        for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
            if (appProcess.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND && appProcess.processName.equals(packageName)) {
                return true;
            }
        }
        return false;
    }

    /**
     * 判斷Service是否正在運行
     *
     * @param context     上下文
     * @param serviceName Service 類全名 如MyService.class.getName()
     * @return true 表示正在運行，false 表示沒有運行
     */
    public static boolean isServiceRunning(Context context, String serviceName) {
        ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningServiceInfo> serviceInfoList = manager.getRunningServices(30);
        if (serviceInfoList == null || serviceInfoList.size() <= 0) {
            return false;
        }
        for (ActivityManager.RunningServiceInfo info : serviceInfoList) {
            if (info.service.getClassName().equals(serviceName)) {
                return true;
            }
        }
        return false;
    }