private async void SendBtn_Click(object sender, RoutedEventArgs e)
        {
            var result = await SendFeedbackAsync();

            if (result)
            {
                FBFormControl.ShowPanel.Begin();
            }
            else
            {
                HideFeedbackForm.Begin();
            }
            FBFormControl.Imagefile = null;
            FBFormControl.SetSupportImageSource(null);
            FBFormControl.FeedbackTextBox.Text = "";
        }
        private async void AddImageBtn_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                var file = await FilePicker.OpenPicker(new List <string>() { ".jpg", ".png" });

                FBFormControl.SetSupportImageSource(await FilePicker.ConvertToBitmapFromFile(file));
                if (file != null)
                {
                    //var encoded = await FilePicker.EncodeFile(file);
                    FBFormControl.Imagefile = file;
                }
            }
            catch
            {
                await HelpersClass.ShowDialogAsync("Lỗi khi thêm hình ảnh");
            }
        }