how not to draw outside a static control?

[code_discuss]

I'm using a static control to draw something on it. the static is in a dialog create by resource editer. It's strange that I can draw outside the static contol, but not outside the dialog. How can I prevent this? I want to draw only inside the static contol.

[Stephen Hewitt]

Check out the CS_PARENTDC windows class style for information on why this happens. One solution is simply not to draw outside the window! Another is to set a clipping region with the GetDCEx function.

Steve

[Michael Dunn]

When you draw in a DC, you can't draw outside the window that the DC is for. So it sounds like you're getting a DC for the dialog, not the control.

--Mike-- Visual C++ MVP :cool: LINKS~! CP SearchBar v3.0 | C++ Forum FAQ I work for Keyser Söze

[Stephen Hewitt]

You can if the window class has the CS_PARENTDC style set. From MSDN:

CS_PARENTDC Sets the clipping rectangle of the child window to that of the parent window so that the child can draw on the parent. A window with the CS_PARENTDC style bit receives a regular device context from the system's cache of device contexts. It does not give the child the parent's device context or device context settings. Specifying CS_PARENTDC enhances an application's performance.

Steve

[code_discuss]

Yes I agree. Thank you very much, you did let know why I have this bug and how I can fix it. I used SelectClipRgn() to fix it, which is similiar to your GetDCEx.

[Michael Dunn]

That looks like an optimization that made sense when our computers were running at 4.77 MHz. ;)

--Mike-- Visual C++ MVP :cool: LINKS~! CP SearchBar v3.0 | C++ Forum FAQ I work for Keyser Söze