Re: child window drawing extends onto dialog

"AliR \(VC++ MVP\)" <AliR@online.nospam>
Fri, 11 Apr 2008 13:54:12 -0500
You can specfiy a clip region:

void CMyCtrl::OnPaint()
   CPaintDC dc(this);

   CRect rect;

   CRgn Rgn;
   CRgn *pOldRgn =

   //do drawing here



"King Menelaus" <> wrote in message

This has got to be something obvious.

I've subclassed a static control on my dialog with a CWnd-derived class,
call it CMyControl. Here's how the control is declared in the rc file:

LTEXT "Static",IDC_STATIC_GRAPH,7,5,240,149

In CMyControl::OnPaint() I do some drawing using CPaintDC::SetPixel().
That works fine. However, if the drawing extends beyond the bounds of
CMyControl's client rectangle (which sometimes happens -- it's data being
read from a machine-control device), I would like it to not be visible.
Instead, it's being drawn onto the parent dialog's background. Do I need
to clip the data to CMyControl's rectangle myself, or is there some style
I'm missing that will do it for me? Why, if I'm drawing to CMyControl's
DC, am I seeing drawing on the dialog?

Much thanks,

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