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I need control( for example button) to draw itself on memory device context.<br />
I created this device context and call ::SendMessage(hwndControl,<wbr /> WM_PAINT,<br />
(WPARAM)memDC.GetSafeHdc()<wbr />, 0). The problem is that in this case invalid<br />
rectangle is empty and control doesn't paint itself. If I specify<br />
InvalidateRect(NULL) before sending message then control does paint itself<br />
on memory DC but it also paints itself on window DC. I also tried to call<br />
ValidateRect(NULL) just after sending message but it doesn't help. How can I<br />
force control to draw itself on memory DC only?<br />
            Thanks.<br />

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I need control( for example button) to draw itself on memory device context.
I created this device context and call ::SendMessage(hwndControl, WM_PAINT,
(WPARAM)memDC.GetSafeHdc(), 0). The problem is that in this case invalid
rectangle is empty and control doesn't paint itself. If I specify
InvalidateRect(NULL) before sending message then control does paint itself
on memory DC but it also paints itself on window DC. I also tried to call
ValidateRect(NULL) just after sending message but it doesn't help. How can I
force control to draw itself on memory DC only?
            Thanks.


Drawing control on memory device context

Kernel and system programming is the process of creating the software necessary for a computer or device to function and operate other programs. Some operating systems (such as Microsoft Windows) are proprietary, but others, such as the various Linux distributions, are open source.