Windows dialog boxes support the use of a default button (pushbutton) that
is automatically activated when the ENTER key is pressed while focus is not
on a command button. The MFC class library will automatically call the
CDialog::OnOK() virtual function for a dialog whenever the default button
(pushbutton) is activated by pressing the ENTER key.
This behavior conforms to the guidelines set forth by "The Windows
Interface: An Application Design Guide." This manual is included with the
Windows version 3.1 SDK documentation. It is also available from Microsoft
Although default button (pushbutton) support is recommended, you might want
to disable or modify the standard implementation in certain situations. You
can do this in an MFC application by following these steps:
- Load the dialog into App Studio and change the OK button identifier
from IDOK to something else such as IDC_MYOK. Also, clear the check from
Default Button property.
- Use ClassWizard to create a message handling function for this
button named OnClickedMyOK. This function will be executed when a
BN_CLICKED message is received from this button.
- In the code for OnClickedMyOK, call the base class version of the
OnOK function. Here is an example:
- Override OnOK for your dialog, and do nothing inside the function. Here
is an example:
- Run the program and bring up the dialog. Give focus to a control other
than the OK button. Press the RETURN key. Notice that CDialog::OnOK()
is never executed.
This technique effectively disables the standard default button
(pushbutton) support in an MFC program. The OK button will continue to
behave as before when activated by the mouse or through a mnemonic
keystroke, but the ENTER key will not trigger OnOK handling.
This same technique can be used to disable or modify default OnCancel
processing. The escape key generates a call to CDialog::OnCancel
just as the enter key generates an OnOK function call.
Article ID: 122489 - Last Review: June 17, 2014 - Revision: 4.0
- Microsoft Foundation Class Library 4.2, when used with:
- Microsoft Visual C++ 1.0 Professional Edition
- Microsoft Visual C++ 4.0 Standard Edition
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.