Replacing the control template of a progress bar

WPF prides itself on separating appearance from behavior. This is more evident with control templates than anything else. A control template is just that: a template for a control's appearance, which does not affect its behavior. In this recipe, we'll take a look at the basics of writing a control template by creating a custom template for a ProgressBar control. In later recipes we'll discuss other, more complex control templates.

Getting ready

Make sure Visual Studio is up and running.

How to do it...

We'll create an alternative control template for a ProgressBar to demonstrate the basics of control template authoring:

1. Create a new WPF application named CH08.CustomProgressBar.

2. Open App.xaml. Add a new resource of type ControlTemplate as follows:

   <ControlTemplate TargetType="ProgressBar" x:Key="pt1">
   </ControlTemplate>

3. Inside the ControlTemplate add the following markup:

   <Grid>
       <Rectangle x:Name="PART_Track">
           &lt...