Create Thumbnail of Uploaded Image or Picture in ASP.Net

Refer

Dynamically generate and display Thumbnail picture by resizing the Image in ASP.Net

using (System.Drawing.Image thumbnail = image.GetThumbnailImage(100, 100, new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback), IntPtr.Zero))

In the above line of code "image.GetThumbnailImage" is underlined and shows message on mousehover that is: Reference to a non-shared member requires an object reference

What version of .Net you are using? It works fine for .Net 3.5+

how to check it?

Right click project and check properties and the code works fine and you are the first one complaining about it.

And more easier download sample code attached