WindowsFormsHost content doesn't show when its given to a ContentPresenter

Question

I have WinForm controls I want to put in a WPF DropDownButtons(Extended WPF Toolkit) DropDownContent. Putting the controls to a WindowsFormsHost and that one is giving to the DropDownContent doesn't work. The Winforms control doesn't visible. In the template the DropDownContent property is a ContentPresenter.

If I want to try this whole story with a common container (StackPanel, Grid, etc.) it works fine.

Does anybody know how can I solve this?

Answer 1

The DropDownButton has a Popup whose AllowsTransparency is set to true - see the template here. You cannot put a WindowsFormsHost into a Popup whose AllowsTransparency is true. You'll have to modify the template for the DropDownButton so that its AllowsTransparency is false.