Question

I have an application that declares textboxes in various places, like in styles and datatemplates, and now I’m in a situation where I need to change every textbox’s standard behavior for getting and losing focus.

What’s a good way to do this?

I was thinking of two solutions: one is to derive a new class from TextBox, which I understand is generally frowned upon. The other is to create some kind of style that uses EventSetters, but since the styles and datatemplates in my application don’t have codebehind files I donno how an event will find the appropriate event handler.

Answer 1

You can create a style that applies to all TextBoxes using the Key property as follows:

<Style x:Key={x:Type TextBox}>
...
</Style>

You can then modify the Template property of the TextBox and use Triggers to add special behavior to the OnGotFocus and OnLostFocus events.