title: Convert an image (selected by path) to base64 string
body: <p>How do you convert an image from a path on the user's computer to a base64 string in C#?</p>
  <p>For example, I have the path to the image (in the format <code>C:/image/1.gif</code>) and would like to have a data URI like <code>data:image/gif;base64,/9j/4AAQSkZJRgABAgEAYABgAAD..</code> representing the <code>1.gif</code> image returned.</p>