How to Disable Default Pushbutton Handling for MFC Dialog

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Windows dialog boxes support the use of a default button (pushbutton) thatis automatically activated when the ENTER key is pressed while focus is noton a command button. The MFC class library will automatically call theCDialog::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 WindowsInterface: An Application Design Guide." This manual is included with theWindows version 3.1 SDK documentation. It is also available from MicrosoftPress.
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Although default button (pushbutton) support is recommended, you might wantto disable or modify the standard implementation in certain situations. Youcan do this in an MFC application by following these steps:

  1. 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.
  2. 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.
  3. In the code for OnClickedMyOK, call the base class version of the OnOK function. Here is an example:
       void CMyDialog::OnClickedMyOK()   {      CDialog::OnOK();   }						
  4. Override OnOK for your dialog, and do nothing inside the function. Here is an example:
       void CMyDialog::OnOK()   {   }						
  5. 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 tobehave as before when activated by the mouse or through a mnemonickeystroke, but the ENTER key will not trigger OnOK handling.

This same technique can be used to disable or modify default OnCancelprocessing. The escape key generates a call to CDialog::OnCanceljust as the enter key generates an OnOK function call.
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Article ID: 122489 - Last Review: 12/04/2015 10:41:45 - Revision: 4.0

Microsoft Foundation Class Library 4.2

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