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4/8/2010

This function is an application-defined callback function that processes messages sent to a modal or modeless dialog box.

Syntax 

BOOL CALLBACK DialogProc(
  HWND 
hwndDlg, 
  UINT 
uMsg, 
  WPARAM 
wParam, 
  LPARAM 
lParam
);

Parameters

hwndDlg

[in] Handle to the dialog box.

uMsg

[in] Specifies the message.

wParam

[in, out] Specifies additional message-specific information.

lParam

[in, out] Specifies additional message-specific information.

Return Value

Typically, the dialog box procedure should return TRUE if it processed the message, and FALSE if it did not. If the dialog box procedure returns FALSE, the dialog manager performs the default dialog operation in response to the message.

If the dialog box procedure processes a message that requires a specific return value, the dialog box procedure should set the desired return value by calling SetWindowLong( hwndDlg, DWL_MSGRESULT, lResult) immediately before returning TRUE. Note that you must call SetWindowLongimmediately before returning TRUE; doing so earlier may result in the DWL_MSGRESULT value being overwritten by a nested dialog box message.

The following messages are exceptions to the general rules:

WM_CTLCOLORBTN

WM_CTLCOLORSCROLLBAR

WM_CTLCOLORDLG

WM_CTLCOLORSTATIC

WM_CTLCOLOREDIT

WM_INITDIALOG

WM_CTLCOLORLISTBOX

WM_QUERYDRAGICON

Consult the documentation for the specific message for details on the semantics of the return value.

Remarks

You should use the dialog box procedure only if you use the dialog box class for the dialog box. This is the default class and is used when no explicit class is specified in the dialog box template. Although the dialog box procedure is similar to a window procedure, it must not call the DefWindowProcfunction to process unwanted messages. Unwanted messages are processed internally by the dialog box window procedure.

Requirements

Header Developer Implemented
Library Developer Implemented
Windows Embedded CE Windows CE 1.0 and later
Windows Mobile Windows Mobile Version 5.0 and later

See Also