Important:
This is retired content. This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This content may contain URLs that were valid when originally published, but now link to sites or pages that no longer exist.
A version of this page is also available for
4/8/2010

This function carries out default message processing for a window procedure belonging to an application-defined dialog box class.

Syntax 

LRESULT DefDlgProc( 
  HWND 
hDlg, 
  UINT 
Msg, 
  WPARAM 
wParam, 
  LPARAM 
lParam
);

Parameters

hDlg

[in] Handle to the dialog box.

Msg

[in] Specifies the message number.

wParam

[in] Specifies additional message-specific information.

lParam

[in] Specifies additional message-specific information.

Return Value

The return value specifies the result of the message processing and depends on the message sent.

Remarks

The DefDlgProcfunction is the window procedure for the predefined class of dialog box. This procedure provides internal processing for the dialog box by forwarding messages to the dialog box procedure and carrying out default processing for any messages that the dialog box procedure returns as FALSE. Applications that create custom window procedures for their custom dialog boxes often use DefDlgProcinstead of the DefWindowProcfunction to carry out default message processing.

Applications create custom dialog box classes by filling a WNDCLASSstructure with appropriate information and registering the class with the RegisterClassfunction. Some applications fill the structure by using the GetClassInfofunction, specifying the name of the predefined dialog box. In such cases, the applications modify at least the lpszClassNamemember before registering. In all cases, the cbWndExtramember of WNDCLASSfor a custom dialog box class must be set to at least DLGWINDOWEXTRA.

The DefDlgProcfunction must notbe called by a dialog box procedure; doing so results in recursive execution.

Requirements

Header winuser.h
Library Dlgmgr.lib
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also