title: Programmatically set the background of a button to be an image
body: <p>how can I programmatically set the background of a button to be an image?
  I know how to do it in XAML, but in code, I keep getting stuck, I tried </p>
  
  <pre><code>Button.Background = new ImageBrush{ ImageSource = "source" };
  </code></pre>
  
  <p>but then I get the error that string cannot be converted to ImageSource.</p>