Adding combo boxes and list boxes (XAML)
Use a ComboBox when you need to conserve on-screen space and when users select only one option at a time. A ComboBox shows only the currently selected item. Users must tap on the control to see other selectable items.
Use a ListBox when you want the options to be visible all the time or when users can select more than one option at a time. ListBox controls are "always open", which allows several items to be displayed to the user while at rest.