DayPath Journal

Songhay.Silverlight.Controls.AnalogDigit, My First Custom Control

SL BiggestBox - Rolling Analog Digit Sample
  • I think I now see where the term “Layout Root” comes from…
  • I don’t think Expression Blend is built for making custom controls—which is why the User-Control concept would be needed.
  • I can now see how an inexperienced developer can ‘hide’ too many visuals inside styles—these folks are trapped in limbo between making a custom control and using styles economically.
  • Importantly, I now see the place where the Dependency Property is the indispensable star of the show! When there is the need to use a Dependency Property in a View Model there is probably a higher need for a custom control.
  • I had too much trouble understanding the purpose of the Dependency Property because I looked at them through the MVVM lens instead of through the needs of the Control.
  • The TemplateBinding declaration that we would expect to work within the scope of a UI Element does not seem to work within the scope of a Style Resource. I lost most of yesterday [2012-03-15] struggling with this.
  • ILSpy (or a similar tool) is essential for learning from the pros (like Telerik) how custom controls are built.
  • Remember all that System.ComponentModel stuff for tooling custom controls for WinForms? Well, here it is for XAML.

As always the source code for this stuff is at

Related Links