This enumeration determines which button should be the default accept button in a MessageBox . The left-most in a left-to-right reading message box is Button1 . public enum MessageBoxDefaultButton { Button1 = 0 , Button2 = 256 , Button3 = 512 } HierarchySystem.Object System.ValueType System.Enum(System.IComparabl, System.IFormattable , System.IConvertible) MessageBoxDefaultButton Passed ToMessageBox.Show() |