private async void OnLogInCompleted(object sender, GoogleClientResultEventArgs <Plugin.GoogleClient.Shared.GoogleUser> loginEventArgs)
 {
     if (loginEventArgs.Data != null)
     {
         Plugin.GoogleClient.Shared.GoogleUser googleUser = loginEventArgs.Data;
         user.Name       = googleUser.Name;
         user.GivenName  = googleUser.GivenName;
         user.FamilyName = googleUser.FamilyName;
         user.Email      = googleUser.Email;
         user.Picture    = googleUser.Picture;
     }
     else
     {
         await PageDialog.DisplayAlertAsync("Error", loginEventArgs.Message, "OK");
     }
     CrossGoogleClient.Current.OnLogin -= OnLogInCompleted;
 }
        void _googleClientManager_OnLogin(object sender, GoogleClientResultEventArgs <Plugin.GoogleClient.Shared.GoogleUser> e)
        {
            if (e.Data != null)
            {
                Plugin.GoogleClient.Shared.GoogleUser googleUser = e.Data;

                User.Name    = googleUser.Name;
                User.Email   = googleUser.Email;
                User.Picture = googleUser.Picture;

                LblUsername.Text     = User.Name;
                LblEmailAddress.Text = User.Email;
                var data = NSData.FromUrl(NSUrl.FromString(User.Picture.AbsoluteUri));
                FullImageView.Image = new UIImage(data);
            }
            BtnLogin.Hidden               = true;
            BtnLogout.Hidden              = false;
            _googleClientManager.OnLogin -= _googleClientManager_OnLogin;
        }