QML working with DirectX

Hi all,

I'm working on a computer graphics project using Qt, I use Qt's Graphics View Framework.
The renderer is based on DirectX.
Also there are some UI elements (buttons, menus) are drawn by qml.

The problem is: the application's main window displays either directX frame buffer or Qt UI elements, not both.
But what I need is the Qt UI elements displayed above directx generated image.

Here is what I'm doing:

QWidget *paintWidgetPtr = view->viewport();

mainScene->InitializeRender( paintWidgetPtr->winId() );

I get the widget of view, and then get its handle, use it to create directx device, thus directx can draw to this window.
Unforgettably qml also draws to this window I think.

The result is In a short time period, directx generated image shows , then after a while, qml generated UI shows, ...

I want qml generated UI overlaps directx image, thus the user can send UI commends.

Please help me to solve this problem.

Thank you for reading.