29.8. Rendering Graphical Data Using the Visual Layer

The final option for rendering graphical data with WPF is termed the visual layer. As mentioned, you can only gain access to this layer through code (it is not XAML-friendly). While a vast majority of your WPF applications will work just fine using shapes, drawings, and geometries, the visual layer does provide the fastest possible way to render huge amounts of graphical data. Oddly, this very low-level graphical layer can also be useful when you need render to single image over a very large area. For example, if you need to fill the background of a window with a plain static image, the visual layer will be the fastest way to do so, and it may be useful if you need to change between window backgrounds very quickly, based on user input or whatnot.

While we won't spend too much time delving into the details of this aspect of WPF programming, let's build a small sample program that illustrates the basics.