DX9'AdaterCount means monitor count.

DX11'AdapterCount meas video card count.

So I can.t get and use the second video card In DX9?

For example My laptop has intel/Nivida video cards.

I can't use nvida card audomatic only use code?

That means When I want use nivida cards with DX11 to render scene and share the backBuffer to DX9( in order to Interaction in WPF ) must update the DX11'Backbuffer with nivida'Device to CPU and new another Texture with intel'Device ,In the end share the Texture handle from DX11 to DX9 with the Same intel card.

Nononono; you don't do something like that. No such thing as generating a texture on nvidia and passing it to intel. No. Just don't.

Most of the time, those two cards are part of a switchable graphics ecosystem. I'm not sure how they are supposed to work and I strongly recommend against even trying to do that in D3D9, let alone mixing APIs!

Thanks! I have give up to do like that! I have give up DX9 and DX11 mix in WPF. now I only use DX11. I think this is the most right way to use DX. Ever I only want to use WPF'S control. Now I decide to use Direct2D1 to made control by myself. I think Maybe the traditional way is the final answer!