Hi ankit.acet13,
Thanks for the reply and thanks for providing the code snippet. Yes, since the C# wrapper project is a community project and it does not include all interfaces in the native SDK, after a brief research, we found out that the part for custom UI in the C# wrapper is actually not containing all custom UI interfaces available in the native Windows SDK. Therefore the Custom UI might not work as expected in the C# wrapper.
I have forwarded this to the engineering team and we will add those interfaces in the C# wrapper in the next release. You could also implement the wrapper code if it this urgent. Pardon the inconvenience caused by this.
Hope this helps. Thanks!