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

I had same problem, I solved this problem by following way.

Right click on page, select Property. in build action select Content.

Hope that this solution may help you.