This message is sent to a dialog box before Windows draws the dialog box. By responding to this message, the dialog box can set its text and background colors by using the given display device context handle. The DefWindowProc function selects the default system colors for the dialog box.
At a Glance
| Header file: | Winuser.h |
| Windows CE versions: | 1.0 and later |
Syntax
WM_CTLCOLORDLG hdcDlg = (HDC) wParam;
hwndDlg = (HWND) lParam;
Parameters
hdcDlg
Handle to the device context for the dialog box
hwndDlg
Handle to the dialog box
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 dialog box.
Default Action
The DefWindowProc function selects the default system colors for the dialog box.
Remarks
The system does not automatically destroy the returned brush. It is the application's responsibility to destroy the brush when it is no longer needed.
The WM_CTLCOLORDLG message is never sent between threads. It is sent only within one thread.
Note that the WM_CTLCOLORDLG message is sent to the dialog box itself; all of the other WM_CTLCOLOR* messages are sent to the owner of the control.
If a dialog box procedure handles this message, it should cast the desired return value to a BOOL and return the value directly. If the dialog box procedure returns FALSE, then default message handling is performed. The DWL_MSGRESULT value set by the SetWindowLong function is ignored.
See Also