DialogProc

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

BOOL CALLBACK DialogProc(

HWND hwndDlg, // handle to dialog box
UINT uMsg, // message
WPARAM wParam, // first message parameter
LPARAM lParam // second message parameter
);  

Parameters

hwndDlg

Identifies the dialog box.

uMsg

Specifies the message.

wParam

Specifies additional message-specific information.

lParam

Specifies additional message-specific information.

Return Values

Except in response to the WM_INITDIALOG message, the dialog box procedure should return nonzero if it processes the message, and zero if it does not. In response to a WM_INITDIALOG message, the dialog box procedure should return zero if it calls the SetFocus function to set the focus to one of the controls in the dialog box. Otherwise, it should return nonzero, in which case the system sets the focus to the first control in the dialog box that can be given the focus.

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 DefWindowProc function to process unwanted messages. Unwanted messages are processed internally by the dialog box window procedure.

DialogProc is a placeholder for the application-defined function name.

See Also

CreateDialog, CreateDialogIndirect, CreateDialogIndirectParam, CreateDialogParam, DefWindowProc, DialogBox, DialogBoxIndirect, DialogBoxIndirectParam, DialogBoxParam, SetFocus, WM_INITDIALOG