/// <summary>
        /// Sign in Background
        /// </summary>
        private bool SignInBackend()
        {
            Log.Logger.Info(Tag, "signInBackend");
            ClearAccountInfo();

            if (service == null)
            {
                return(false);
            }

            CountDownLatch countDownLatch = new CountDownLatch(1);

            Huawei.Hmf.Tasks.Task task = service.SilentSignIn();
            task.AddOnSuccessListener(new OnSuccessListener(delegate(Java.Lang.Object authHuaweiId)
            {
                Log.Logger.Info(Tag, "silentSignIn success");
                DealSignInResult((AuthHuaweiId)authHuaweiId);
                countDownLatch.CountDown();
            }
                                                            ));

            task.AddOnFailureListener(new OnFailureListener(delegate(Java.Lang.Exception authHuaweiId)
            {
                Log.Logger.Info(Tag, "silentSignIn error");
                countDownLatch.CountDown();
            }
                                                            ));

            try
            {
                countDownLatch.Await(15, TimeUnit.Seconds);
            }
            catch (Java.Lang.InterruptedException e)
            {
                Log.Logger.Info(Tag, "signInBackend catch InterruptedException");
                countDownLatch.CountDown();
            }

            if (TextUtils.IsEmpty(AccessToken))
            {
                return(false);
            }
            else
            {
                return(true);
            }
        }
 /// <summary>
 /// Silently Signing In With HUAWEI ID
 /// </summary>
 private void SilentSignIn()
 {
     try
     {
         Task silentSignInTask = authManager.SilentSignIn();
         silentSignInTask.AddOnSuccessListener
         (
             new OnSuccessListener
             (
                 "SilentSignIn Success"
             )
         ).AddOnFailureListener(
             new OnFailureListener
             (
                 "SilentSignIn Failed"
             )
             );
     }
     catch (System.Exception e)
     {
         //if Failed use SignIn
         SignIn();
     }
 }