WPF window flickering with DirectX during resizing

I have an issue with WPF window.

Now I use C++/CLI to create code for my DX11 engine. In this code I create WPF window and use it for D3D11 output.

I make rendering in another thread and everything works great except one thing:

window flickering when I resize it (white background is visible for a few milliseconds when I keep resizing a window).

Could anyone help me to solve this problem to get rid of this annoying flickering effect?

I`d prefer to do this without making window transparent, if possible.