"The type or namespace name 'Autodesk' could not be found" error.

[ranga.narasimhan]

I am unable to build following .Net sample (for acad 2017 using vs 2017). I have .net framework to 4.5.

https://adndevblog.typepad.com/autocad/2014/12/drawing-preview-in-wpf-palette.html

I get "The type or namespace name 'Autodesk' could not be found" error.

What's the issue? I get these kinds of error whenever I use old codes and I get stuck up.

Thanks