Using WTL's Cdoublebufferimpl class makes it easy to implement double buffering without having to implement cumbersome code yourself, not only to draw a general window, but also to draw the background of a dialog box.
First #include <atlframe.h>
Secondly, the class needing double buffering drawing should derive from Cdoublebufferimpl<>
Class Cmaindlg:public Cdialogimpl<cmaindlg>, Public cdoublebufferimpl<cmaindlg>{}
Then the message chain joins
BEGIN_MSG_MAP_EX (CMAINDLG)
//....
Chain_msg_map (cdoublebufferimpl<cmaindlg>)
End_msg_map ()
Finally write the DoPaint function, directly to draw on the
void DoPaint (Cdchandle DC)
{//Draw a rectangle
dc. Rectangle (0, 0, 10, 10);
}
Into the.
Note that because the Cdoublebufferimpl class responds to WM_PAINT messages and WM_ERASEBKGND messages, there is no need to respond in your own class.
