WM_CTLCOLORBTN Overview  Group

The WM_CTLCOLORBTN message is sent to the parent window of a button when the button is about to be drawn. By responding to this message, the parent window can set a button’s text and background colors.

WM_CTLCOLORBTN 

hdcButton = (HDC) wParam;   // handle of button display context 

hwndButton = (HWND) lParam; // handle of button 

 

Parameters

hdcButton

Value of wParam. Identifies the display context for the button.

hwndButton

Value of lParam. Identifies the button.

Return Values

If an application processes this message, it must return the handle of a brush. Windows uses the brush to paint the background of the button.

Default Action

The DefWindowProc function selects the default system colors for the button.

Remarks

The WM_CTLCOLORBTN message is never sent between threads. It is sent only within one thread.

The text color of a check box or radio button applies to the box or button, its check mark, and the text. The focus rectangle for these buttons remains the system default color (typically black). The text color of a group box applies to the text but not to the line that defines the box. The text color of a push button applies only to its focus rectangle; it does not affect the color of the text.

See Also

DefWindowProc, RealizePalette, SelectPalette, WM_CTLCOLORDLG, WM_CTLCOLOREDIT, WM_CTLCOLORLISTBOX, WM_CTLCOLORMSGBOX, WM_CTLCOLORSCROLLBAR, WM_CTLCOLORSTATIC