Toolkit Pro - Transparent checkbox?

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Transparent checkbox?

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Category: Codejock Products
Forum Name: Toolkit Pro
Forum Description: Topics Related to Codejock Toolkit Pro
URL: http://forum.codejock.com/forum_posts.asp?TID=6731
Printed Date: 19 August 2025 at 7:17pm
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Topic: Transparent checkbox?

Posted By: znakeeye
Subject: Transparent checkbox?
Date Posted: 26 March 2007 at 9:12am

I have a CWnd-derived window with a black background. Inside this window, I have a checkbox (CButton) with the WS_EX_TRANSPARENT style set. Of course, the rectangle of this checkbox is excluded in CMyWindow::OnPaint, using ExcludeClipRect.

Why does my checkbox look like this? How do I make it transparent?

Thanks!

Replies:

Posted By: Oleg
Date Posted: 26 March 2007 at 10:36am

Hi,

in MSDN see WM_CTLCOLOR description/sample.

-------------
Oleg, Support Team
CODEJOCK SOFTWARE SOLUTIONS

Posted By: znakeeye
Date Posted: 26 March 2007 at 12:04pm

Hi,

The problem is that WM_CTLCOLOR is not received. I've tried to capture WM_CTLCOLORBTN too, with no success.

Here is my code:

In the message map of my CWnd-derived class: ON_WM_CTLCOLOR()

CMyDerivedWnd::Create(...):

m_button.CreateEx(WS_EX_TRANSPARENT, _T("BUTTON"), _T("&Transparency?"), WS_VISIBLE | WS_CHILD | WS_CLIPCHILDREN | WS_CLIPSIBLINGS | BS_CHECKBOX, rcButton, this, IDC_MYBUTTON);

HBRUSH CMyDerivedWnd::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor)
{

// Never called... could this be due to the BS_CHECKBOX style?
return CWnd::OnCtlColor(pDC, pWnd, nCtlColor);
}

Any ideas? What am I missing here?

Posted By: Oleg
Date Posted: 27 March 2007 at 1:14am

Hi,

WM_CTLCOLOR is sent to parent of button. In button you can catch reflected message:

ON_WM_CTLCOLOR_REFLECT()

HBRUSH CMyDerivedWnd::CtlColor(CDC* pDC, UINT nCtlColor)
{

pDC->SetTextColor( m_clrText );    // text
pDC->SetBkColor( m_clrBkgnd );    // text bkgnd
return m_brBkgnd;                // ctl bkgnd

}

-------------
Oleg, Support Team
CODEJOCK SOFTWARE SOLUTIONS

Posted By: znakeeye
Date Posted: 27 March 2007 at 9:22am

I've done some testing, and it seems that WM_CTLCOLOR is only sent to the parent window if it has been created from a dialog resource. My CWnd-derived class does not receive this message. Do you know the cause of this?

Anyway, I will try your solution, though I did not want to create another button class

Thanks for your advice!

Posted By: znakeeye
Date Posted: 29 March 2007 at 3:24am

It's not working :(. Even if I subclass CButton and override WM_CTLCOLOR, as you described, I do not get this message. Neither is it handled in CMyWindow::PreTranslateMessage.

WM_CTLCOLOR is not sent to the parent window. What can be the reason for this? This is what I know:

1) My parent window is a modeless dialog (most of the code was taken from CColorSelectorCtrl).

2) My check box is created dynamically in CMyWindow::Create(...).

To reproduce this, all you need to do is adding a check box in the color picker control and then try making it transparent.

Any ideas? Thanks.

Posted By: Oleg
Date Posted: 29 March 2007 at 4:05am

Hi,

Attach modified project and I will point what you do wrong.

-------------
Oleg, Support Team
CODEJOCK SOFTWARE SOLUTIONS