How do I make toolbar button expandable?

Question

I want to have a button on my toolbar that has a little down arrow that when I press, gives me sub toolbar options. Think of the Undo/Redo buttons in Visual Studio; when I click the arrow next to the icon it pops open the list of edits I can go back to.

Answer 1

Use a split button. See this example.

Answer 2

I've done something similar using Menus/MenuItems. You can style your MenuItems to fit your liking, and still achieve the toggle dropdown functionality.