title: BitmapSource to point to local file
body: <p>What's the best pattern to implement a local cache for a Metro Style App so that the images can be cached in the background while the app is being used on-line and to serve images when the App goes offline?</p>
  
  <p>How do we set a BitmapSource to a local file upon discovering the lack of internet access? using new Uri(localpath, UriKind.Absolute) doesn't work.</p>