How to set transparent background for static control?

Question

5.00/5 (2 votes)

See more:

I created a window using CreateWindowEx() function.
On this window I place static control which was created like that:

C++

HWND hStatic;
hStatic = CreateWindowEx( WS_EX_TRANSPARENT ,
TEXT("Static"),
TEXT("text"),
WS_CHILD ,
10,
80,
250,
70,
CtrlsWndHnd, //parent
NULL,
hInstance,
NULL);
ShowWindow(hStatic,SW_SHOW);
UpdateWindow(hStatic);

Control has been successfully created.
And now I try to make transparent background using this code:

C++

//inside parent window procedure:
case WM_CTLCOLORSTATIC:
{
HDC hdcStatic = (HDC) wParam;
SetBkColor(hdcStatic,TRANSPARENT);
return (INT_PTR)(HBRUSH)GetStockObject(NULL_BRUSH);
}
break;

But result is black background of static control.
What I did wrong? Where is mistake?

Posted 15-Jun-13 10:33am

Igor-84

Add a Solution

2 solutions

Solution 2

Ian A Davidson, great thanks! The problem was here:
1. instead of:

C++

SetBkColor(hdcStatic,TRANSPARENT);

needed to write:

C++

SetBkMode(hdcStatic,TRANSPARENT);

2. here I returned null brush:

C++

return (INT_PTR)(HBRUSH)GetStockObject(NULL_BRUSH);

but needed to return valid background color:

C++

HBRUSH BGColorBrush = CreateSolidBrush(RGB(230,230,230));
//...
return (LRESULT)BGColorBrush;

Posted 15-Jun-13 13:15pm

Igor-84

Comments

thepen 28-Sep-22 10:31am

Actually, NULL_BRUSH return worked for me, not the other.

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Ian A Davidson · Accepted Answer · 2013-06-15T12:15:00

My initial guess is that you need to handle the WM_ERASEBKGND message for the control, and return non-zero to indicate that the background doesn't need to be erased.

It also looks as if you are probably setting the background colour to black yourself (SetBkColor takes a COLORREF, so "TRANSPARENT" is probably interpreted as a black, or near black, colour). You need to set the background mode to transparent instead:

C++

SetBkMode (hdcStatic, TRANSPARENT);

However, it seems you shouldn't be returning a null brush, according to the following link, where exactly the same question was asked, and seems to be solved: http://www.cplusplus.com/forum/windows/73999/[^]

Regards,
Ian.