How to get a thumbnail of a window in C#?

How do you go about getting a thumbnail of a window, like Windows 7 superbar preview, or Aero flip? Note that I do not want a screenshot of the application, there is a way in DWM to get this information.

I would like a C# way of doing this.

Thanks

What is the thumbnail of a window?

What Are Thumbnails Anyway? By default, instead of using generic icons for documents, Windows 10 creates small pictures of image or document contents called thumbnails. These tiny images are stored in a special database file called the thumbnail cache.

Where is the thumbnail on a computer?

Thumbnails are an option in file managers, such as Windows Explorer, and they are found in photo editing and graphics programs to quickly browse multiple images in a folder.

Already been done by Bart de Smet, he used the new Vista DWM api to achieve that.

alt text