private async void viewImage_Click(object sender, RoutedEventArgs e)
{
var renderer = new ImageRenderer(new HostConfig(), this.Resources);
var imageStream = renderer.RenderAdaptiveCard(this._card, 480);
string path = System.IO.Path.GetRandomFileName() + ".png";
using (FileStream fileStream = new FileStream(path, FileMode.Create))
{
await imageStream.CopyToAsync(fileStream);
}
Process.Start(path);
}