Creating a ComboBox/Drop Down Type UserControl in WPF

How can I ComboBox/Drop Down Type User Contro开发者_开发百科l. I want to have a control where a TextBox is displayed by default, then when the user clicks/focuses the textbox, have a "Drop Down" appear that contains a bunch of other controls, when the textbox/usercontrol loses focus eg. user clicks elsewhere, the "Drop Down" should disappear

you can try

AutoCompleteTextBox in WPFToolkit

http://wpf.codeplex.com/