title: How to calculate the size of a piece of text in Win2D
body: <p>I am writing an application for Windows 10 using Win2D and I'm trying to draw a shape which scales dynamically to fit whatever text happens to be in it.</p>
  
  <p>What I'd like to do is work out how big a particular string would be with a given CanvasTextFormat and then use that to set the size of the shape.</p>
  
  <p>My problem is I can't seem to find a way of working out how big the string will be?</p>