Question

I want to create a custom control that extends a built-in control and then has a template that wraps that control with a container?

The C# class:

class ExtraBorderTextBox : TextBox {}

The Xaml:

<ControlTemplate>
    <Border>
        <TextBox/>
    </Border>
</ControlTemplate>

That doesnt’ work because the TextBox in the control template isn’t my custom control, it is a second instance.

I need access to the properties and events on TextBox, having a different parent doens’t make sense, I would have to replicate all of that in my class.

This is a simplified example; imagine Border being replaced with a ContentControl that has a 50 line control template for itself. I guess I want something like ContentPresenter (like I have in the ContentControl), but there isn’t anything like a “ControlPresenter”. Right? Am I missing something, or am I stuck with replicating my content control for the TextBox, or replicating the TextBox behaviour and presentation for my content control?

Thanks.

Update:
There is an answer here that does what I want, which is to copy the default template for System.Windows.Controls.TextBox. This will do what I want; I can insert my container into that. I was hoping that WPF provided a way that is more maintainable to do something like this, something like a adorner/decorator pattern.

Is there any way to make this better in some way? Would using something like Expression Blend make this so that I don’t have to hand-edit the XAML pasted in from the webpage?

Answer 1

You could use the default control template as a base and modify it. The default control templates can be found here: http://msdn.microsoft.com/en-us/library/aa970773.aspx