Draw parent pixel on a Control Client Area

Posted on 2002-07-14
Last Modified: 2013-11-20
i want to make some pixels transparent on my control, i need to do that by drawing the parent's pixels that lies behind the intended pixel on the control instread of it ( instead of the pixels on the controls), so how can i do that without setting the control window style to WS_EX_TRANSPARENT  ??
Question by:raqadi
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Expert Comment

ID: 7152761
You cannot -- there is no way to find out for sure what a specific pixel should be if a window obscuring it wasn't there. It is there and thus the OS doesn't care about what it WOULD be otherwise. Why are you so opposed to using the way to go (i.e. use WS_EX_TRANSPARENT)?

Author Comment

ID: 7153494
The problem is that im drawing my control using RoundRect function, but the corners of the control rectangle that will remains out of the rounded rectangle still have a color, i want these corners to be removed, and i dont find any way to do that...!!
LVL 31

Expert Comment

ID: 7153723
Maybe you need to override WM_ERASEBKGND message to avoid the enclosing rectangle is filled with background color.
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Author Comment

ID: 7153736
mr Zoppo, do you mean that the background of my control Appears on those corners ??
LVL 31

Accepted Solution

Zoppo earned 100 total points
ID: 7153764
Well, I guess so ... BTW, I found another interesting thing.
Take a look at;en-us;Q125669

There it's stated that one should use SetWindowRgn() to create
none-rectangular windows. Try this first.
LVL 31

Expert Comment

ID: 7153767
BTW, there's no need to call me 'mr' :o)
(only makes me feeling old)

Author Comment

ID: 7153807
Thanx Zoppo; my dear :0).

im soo happy now, and you are the cause.
LVL 31

Expert Comment

ID: 7153814
You're welcome,

I'm glad that I could help you :)

havea nice day,



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