Down Base. Up Button Method
When overridden in a derived class, handles the clicking of the up button on the spin box (also known as an up-down control).
public: abstract void UpButton();
public abstract void UpButton ();
abstract member UpButton : unit -> unit
Public MustOverride Sub UpButton ()
Notes to Implementers
When overriding this method in a derived class, be sure to call the UpdateEditText() method.