From Xojo Documentation

Property (As MessageDialogButton )
aMessageDialog.ActionButton = newMessageDialogButtonValue
MessageDialogButtonValue = aMessageDialog.ActionButton

Supported for all project types and targets.

The button that performs the default action.


The ActionButton's Visible property is True by default. By default, its caption is "OK" or an equivalent in the language used by the application. To be safe, you should set the caption property explicitly.


The following example creates and manages a "Save Changes" dialog box without the need to create an instance of the Window class.

Var d As New MessageDialog // declare the MessageDialog object
Var b As MessageDialogButton // for handling the result
d.Icon = MessageDialog.GraphicCaution // display warning icon
d.ActionButton.Caption = "Save"
d.CancelButton.Visible = True // show the Cancel button
d.AlternateActionButton.Visible = True // show the "Don't Save" button
d.AlternateActionButton.Caption = "Don't Save"
d.Message = "Do you want to save changes to this document before closing?"
d.Explanation = "If you don't save, your changes will be lost. "

b = d.ShowModal // display the dialog
Select Case b // determine which button was pressed.
Case d.ActionButton
// user pressed Save
Case d.AlternateActionButton
// user pressed Don't Save
Case d.CancelButton
// user pressed Cancel
End Select