Why can't I reference System.ComponentModel.DataAnnotations?

Question

I\'m trying to use DataAnnotations in my WPF project to specify a maximum length of strings, with the following:

using System.ComponentModel.DataAnnotations;         


        

Answer 1

If you don't have it in references (like I did not) you can also add the NuGet System.ComponentModel.Annotations to get the assemblies and resolve the errors. (Adding it here as this answer still top of Google for the error)