Group Items in a listbox alphabetically

I 开发者_如何学Gohave a WPF ListBox which shows a list of employees names. I want to group and sort them alphabetically. Is this possible? if so, how? Also, i will be required to style the headers (like the attached image) Could some1 guide me as to how i can achieve this. Thanx!

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You can group items by adding GroupDescription to the CollectionView. See this related question:

How do I group items in a WPF ListView

Also, google GroupDescription for many more examples.