From Xojo Documentation

Property (As String )
aMessageDialogButton.Caption = newStringValue
StringValue = aMessageDialogButton.Caption

Supported for all project types and targets.

The text displayed in the button.


Place a single "&" in front of any character to make it the shortcut key for the button. For example "&Don't Save" makes "D" the shortcut key.


This example sets Captions of the buttons.

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.AlternateActionButton.Cancel = True // sets AlternateAction button to cancel
d.Title = "This is the Title (Windows & Linux)"
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.ShowModalWithin(Window1) //display the dialog in the window
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