I am not sure, from your question, if you are having problems in capturing the video, or just in displaying it.
If the problem is the display then there are two classes that may help you.
MediaElement
example :-
A simple WPF media player with media item list[
^] and
MediaPlayer MSDN page[
^].
If it is in capturing the video then you should not be confused by the fact that it is WPF. The process is the same as you have already done in C#. Always remember WPF stand for Windows
Presentation Framework. It is about presenting stuff, not processing data. So most of the work in a WPF application will be done in the code behind.
Hope this helps.