private async Task <Tuple <string, string> > GetImageDataAsync(string id, string imageType) { // <img alt="..." src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADIA..." /> var image = await _imageFileService.GetImageAsync(id, imageType); if (image == null) { return(Tuple.Create(imageType, (string)null)); } var data = "data:image/png;base64," + image.ToBase64String(); return(Tuple.Create(imageType, data)); }