RibbonBarSplitButton introduces the following properties, which can be used to define its behavior.
    
    
        - 
            EnableButtonSelection allows buttons inside the drop-down to be selected as default,
            once they are clicked. In the example you can select a Hat for instance, and this
            will trigger several actions - update the image with the selected "hat", update
            the text with the name of the selected hat and, last but not least, update the default
            action of the split button.
        
- 
            SelectedButtonIndex on the other hand can be used, both, to select a button statically
            (without the option of selecting another through a click in the drop-down) and in
            combination with EnableButtonSelection=True, when it can be used to monitor the
            selection for example, or to alter the default logic of EnableButtonSelection=True.
        
        One important thing to mention about this feature of RibbonBarSplitButton is
        the logic in which the image and text are updated:
    
    
        - 
            The text of the split button is gathered from selected button only if it's not set (splitButton.Text=...)
        
- 
            The Image is updated as follows
            
                - 
                    if there is an applicable image set directly to the splitButton (splitButton.ImageUrl = ... or splitButton.DisabledImageUrlLarge etc.), it's applied
                
- 
                    if there is no such image, the split button will try to apply an image from the SelectedButton. If there still isn't an image to apply, the default image is applied.