android判断应用是否在后台运行的方法

 //检查应用是否在后台运行
    public static boolean isBackground(Context context) {
        ActivityManager activityManager = (ActivityManager) context
                .getSystemService(Context.ACTIVITY_SERVICE);
        KeyguardManager keyguardManager = (KeyguardManager) context.getSystemService(KEYGUARD_SERVICE);

        List appProcesses = activityManager
                .getRunningAppProcesses();
        for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
            if (TextUtils.equals(appProcess.processName, context.getPackageName())) {
                boolean isBackground = (appProcess.importance != ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND && appProcess.importance != ActivityManager.RunningAppProcessInfo.IMPORTANCE_VISIBLE);
                boolean isLockedState = keyguardManager.inKeyguardRestrictedInputMode();
                return isBackground || isLockedState;
            }
        }
        return false;
    }