DirectDraw and Sigln-Document Program

[natty]

hello, I am new about directdraw, I recently setup directx9 and wanna load and display some pictures in my MFC program.

Here are my steps:

the MFC program is a single document program and created by the AppWizard and the VIEW class is derived from CScrollView.

Firstly I created a primary surface and a offscreen surface in CMainFrame::OnCreateClient();

Then in OnCreateClient(), I use BitBlt() to copy some picture files onto the offscreen surface.

Finally,in CMyView::OnDraw(), I use Blt() to copy the offscreen surface to primary surface.

The program is running all right , But when I OnSize or Drag the HBar(VBar), the picture should move but not.

I think that the coordinate argument of the Blt() should be a variable instead of a constant, and I need to add some codes in

OnHScroll(), OnVScroll(), OnSize(), OnMove().

So there are two questions I would like to ask:

1.Is my method RIGHT if I want to use directdraw in View in a single document program ?

2.Whether I need to manually override and add some codes in OnMove(),OnSize(),etc. And what codes should I add? Is there any sample?

the second question has made me nearly mad, I found lots of sample and document, but all of them is just display a picture in VIEW, never mentioned the movement situation.

Thank you !