A SetupHookProc hook procedure is an application-defined or library-defined callback procedure that is used with the Print Setup common dialog box. The hook procedure receives messages or notifications intended for the default dialog box procedure.
UINT APIENTRY SetupHookProc(
| HWND hdlg, | // handle to the dialog box window |
| UINT uiMsg, | // message identifier |
| WPARAM wParam, | // message parameter |
| LPARAM lParam | // message parameter |
| ); |
Parameters
hdlg
Handle to the Print Setup common dialog box window for which the message is intended.
uiMsg
Identifies the message being received.
wParam
Specifies additional information about the message. The exact meaning depends on the value of the uiMsg parameter.
lParam
Specifies additional information about the message. The exact meaning depends on the value of the uiMsg parameter.
Return Values
If the hook procedure returns zero, the default dialog box procedure processes the message.
If the hook procedure returns a nonzero value, the default dialog box procedure ignores the message.
Remarks
The Print Setup dialog box has been superseded by the Page Setup dialog box, which should be used by new applications written for Windows NT or Windows 95. However, for compatibility with earlier versions of Windows, the PrintDlg function continues to support display of the Print Setup dialog box. You can provide a SetupHookProc hook procedure for the Print Setup dialog box to process messages or notifications intended for the dialog box procedure.
To enable the hook procedure, use the PRINTDLG structure that you passed to the dialog creation function. Specify the address of the hook procedure in the lpfnSetupHook member and specify the PD_ENABLESETUPHOOK flag in the Flags member.
The default dialog box procedure processes the WM_INITDIALOG message before passing it to the hook procedure. For all other messages, the hook procedure receives the message first. Then, the return value of the hook procedure determines whether the default dialog procedure processes the message or ignores it.
If the hook procedure processes the WM_CTLCOLORDLG message, it must return a valid brush handle for painting the background of the dialog box. In general, if the hook procedure processes any WM_CTLCOLOR* message, it must return a valid brush handle for painting the background of the specified control.
Do not call the EndDialog function from the hook procedure. Instead, the hook procedure can call the PostMessage function to post a WM_COMMAND message with the IDABORT value to the dialog box procedure. Posting IDABORT closes the dialog box and causes the dialog box function to return FALSE. If you need to know why the hook procedure closed the dialog box, you must provide your own communication mechanism between the hook procedure and your application.
You can subclass the standard controls of the common dialog box. However, the common dialog box procedure may also subclass the controls. Because of this, you should subclass controls when your hook procedure processes the WM_INITDIALOG message. This ensures that your subclass procedure receives the control-specific messages before the subclass procedure set by the dialog box procedure.
SetupHookProc is a placeholder for the application-defined or library-defined function name. The LPSETUPHOOKPROC type is a pointer to a SetupHookProc hook procedure.
See Also
EndDialog, PrintDlg, PRINTDLG, PostMessage, WM_INITDIALOG, WM_CTLCOLORDLG