Re: How do I avoid OnPaint call?

"AliR" <AliR@online.nospam>
Thu, 17 Sep 2009 15:14:49 -0500
The code for the OScope is fine, the drawing of the control is done using
double buffering and the memory dc is bitblted on to the screen dc in

So if you try to add something to what is displayed on the OScope image,
without drawing it to m_dcPlot, then it will get erased the next time the
control is repainted and/or when then COScopeCtrl::InvalidateCtrl is called.
If you want to do this correctly, you will have to draw on the m_dcPlot and
invalidate the window.

If I was doing this I would Create a virtual method in COScopeCtrl for what
you want to do, leave it blank. But call it at the end of the InvalidateCtrl
routine, right before the call to InvalidateRect.

Now inherite from COScopeCtrl, and override the method you just created in
COScopeCtrl, and do your drawing in there.
Also add a method that sets the data for what you want to display, and at
the end of that method call InvalidateCtrl, which will redraw the control
and include your changes. (See COScopeCtrl::SetXUnits(...) for an example
of what I'm talking about.)


"???? ????? ??????" <> wrote in message
some drawing is outside the OnPaint()

Graph disappear only in the case of OnSize, Minimize/maximize the
If another application covered this then its working fine

I use this control for drawing


On Sep 17, 7:33 pm, "AliR" <A...@online.nospam> wrote:

I meant least of your problems, not list.

Anyway the point is to put any code that draws on the window in the


"AliR" <A...@online.nospam> wrote in message


At what point are you drawing the graph? If you are doing it anywhere
besides in the WM_PAINT handler, that's where you need to put it.

If you don't then resize or maximize/minimize will be the list of your
problems, if your app gets covered by another the same thing will

The purpose of WM_PAINT is for the system to tell the window that it
to repaint its content. Otherwise it would not be sent to your window.


"Manoj Jangid" <> wrote in message

I have a dialog based application this dialog contain a custom graph
control. this control derived from CWnd class.

When I resize or maximize/minimize my application, existing
information from graph is erased, how do I keep this information

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