Render WPF control on top of WindowsFormsHost

This "airspace" issue is suppose to be fixed in WPF vNext. There are a couple solutions out there, such as here, here, and here.

One way to do this is to host the WPF content in a transparent Popup or Window, which overlays the Interop content.

Late to the party, I know, but I recently came across this issue using a WebBrowser control.

The final fix was to create a screenshot of the web browser whenever I hosted a modal dialog over the top. Since this was a little fiddly, I turned it into a Github project, hopefully this helps a little -

https://github.com/chris84948/AirspaceFixer

(It's on Nuget too, under AirspaceFixer)

Once you have the project all you need to do is this

xmlns:asf="clr-namespace:AirspaceFixer;assembly=AirspaceFixer"

<asf:AirspacePanel FixAirspace="{Binding FixAirspace}">
    <WebBrowser x:Name="Browser" />
</asf:AirspacePanel>

Where FixAirspace is the dependency property that switches from the "real" view of the content, to the screenshot or "fake" view.