Passing parameters to a template

Question

Say I have defined a button with rounded corners.

<Style x:Key="RoundButton" TargetType="Button">
    <!-- bla bla -->
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Border CornerRadius="0,5,5,0" />
                <!-- bla bla -->
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

I it possible that the user of this button can specify the CornerRadius? Can I use a TemplateBinding? But where should I bind to? (to Tag?)

Answer 1

In addition to Kent's suggestions, you could also create an attached property to define the CornerRadius on the button, and bind to that property in the template

Answer 2

In order to use a TemplateBinding, there must be a property on the templated control (Button, in this case). Button does not have a CornerRadius or equivalent property, so your options are:

• hard code the value in the template
• Hijack another property (such as Tag) to store this information. This is quicker, but lacks type safety, is harder to maintain, and prevents other uses of that property.
• Subclass Button and add the propery you need, then provide a template for that subclass. This takes a little longer but yields a much nicer experience for consumers of your control.