Commonly Overridden Member Functions
The following table lists the most likely member functions to override in your CDialog-derived class.
Commonly Overridden Member Functions of Class CDialog
| Member function | Message it responds to | Purpose of the override |
|---|---|---|
OnInitDialog |
WM_INITDIALOG | Initialize the dialog box's controls. |
OnOK |
BN_CLICKED for button IDOK | Respond when the user clicks the OK button. |
OnCancel |
BN_CLICKED for button IDCANCEL | Respond when the user clicks the Cancel button. |
OnInitDialog, OnOK, and OnCancel are virtual functions. To override them, you declare an overriding function in your derived dialog class using the MFC Class Wizard.
OnInitDialog is called just before the dialog box is displayed. You must call the default OnInitDialog handler from your override — usually as the first action in the handler. By default, OnInitDialog returns TRUE to indicate that the focus should be set to the first control in the dialog box.
OnOK is typically overridden for modeless but not modal dialog boxes. If you override this handler for a modal dialog box, call the base class version from your override — to ensure that EndDialog is called — or call EndDialog yourself.
OnCancel is usually overridden for modeless dialog boxes.
For more information about these member functions, see class CDialog in the MFC Reference and the discussion on Working with Dialog Boxes in MFC.