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Editorial Team
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Asked: 2026-05-30T07:28:55+00:00

I have a problem with MFC dialog boxes that are drawn using derived MFC

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I have a problem with MFC dialog boxes that are drawn using derived MFC classes for custom drawing of controls.

One of our customers has a real slow PC with a poor graphics card and even normal Windows dialogs paint quite slow. In our case, the problem is far worse. Each individual control (e.g. buttons, group boxes, labels) can be seen to draw seperately.

In most cases I’ve overridden/implemented the OnPaint() handlers, thinking that drawing on whatever device context I’m provided should be the way to go.

Ideally, what I would like to do is have all controls painted on an off-screen buffer so that when a dialog repaint is required – bang – it just copies the single rendered image to the screen, rather than painting each control to the screen one by one.

Can somebody please advise me how I can achieve this kind of double-buffering?

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1 Answer

  1. Editorial Team

    I’ve sort of found the solution to my problem.. By setting the dialog extended style to WS_EX_COMPOSITED, the drawing works nicely.. The problem I’m having now concerns a continuous stream of WM_PAINT and WM_ERASEBKGND messages that I keep getting when this style is enabled.

    Does anyone know how I can stop the WM_PAINT/WM_ERASEBKGND messages from continously occurring?

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