How can I color background of Edit and Static and other controls?
Windows decides the foreground and background color of any window using current applied theme and color scheme. Windows programming does not provide any property to set the background color of any window widgets. But these are not rigid; programmer can alter these colors if needed. This is essential when programmer wants some control to have different color to highlight it before user or to give some notification to the user. This background property can be modified during handing specific window message called WM_CTLCOLORXXX. Windows sends WM_CTLCOLORXXX message just before drawing of the control. Thus Programmer can alter requited parameters while handing the message.
Message series number is WM_CTLCOLORXXX where XXX is the name of the call of the widget. Say for example for coloring EDIT box message is WM_CTLCOLOREDIT and thus for label/static window it will be WM_CTLCOLORSTATIC.
WM_CTLCOLORXXX : Windows sends these messages before drawing the control. HDC of the child window will be in wParam and HWND will be available in lParam. STATIC, BUTTON, EDIT, LIST, DLG, SCROLLBAR falls under these group. Followings are the name of individual messages.
- WM_CTLCOLORMSGBOX (0x0132)
- WM_CTLCOLOREDIT (0x0133)
- WM_CTLCOLORLISTBOX (0x0134)
- WM_CTLCOLORBTN (0x0135)
- WM_CTLCOLORDLG (0x0136)
- WM_CTLCOLORSCROLLBAR (0x0137)
- WM_CTLCOLORSTATIC (0x0138)
WM_CTLCOLOREDIT hdc = (HDC) wParam; // handle to display context hwnd = (HWND) lParam; // handle to control window
Parameters -
hdc - Value of wParam. Handle to the device context for the control window.
hwnd - Value of lParam. Handle to the window control.
Return Values
If an application processes this message, it must return the handle of a brush. The system uses the brush to paint the background of the edit control.
Default Action
The DefWindowProc function selects the default system colors for the edit control.
case WM_CTLCOLORSTATIC:
{
HDC hdcStatic = (HDC) wParam;
SetTextColor(hdcStatic, RGB(0,0,255));
SetBkColor(hdcStatic, RGB(250,250,0));
return (INT_PTR)CreateSolidBrush(RGB(250,250,0));
}
case WM_CTLCOLOREDIT:
{
HDC hdcStatic = (HDC) wParam;
SetTextColor(hdcStatic, RGB(0,0,255));
SetBkColor(hdcStatic, RGB(0,230,0));
return (INT_PTR)CreateSolidBrush(RGB(0,230,0));
}
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