How to use the Windows Vista TaskDialog in WPF

Introduction

Windows Vista comes with an new standard dialog box called task dialog. The TaskDialog was developed as part of Windows Vista's "clarity" offensive to improve the user experience. It provides a lot more features than the original message box.
The TaskDialog is part of the comctrl32.dll library and only available on Windows Vista or later, its not part of WPF or the .NET framework. To use it from managed code, we need to write a interop wrapper.
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