Entity Framework is not working in class library project

Question

I have created a class library project in VS2010 ultimate with .net 4.0 and Entity fwk-4.1.

After adding a ref to the Entity framework dll, I am not able to use the Data Annotation attributes like 'Required' on class properties.

Could you please let me know what is the solution?

Answer 1

Required attribute is defined inside System.ComponentModel.DataAnnotations namespace and is available in System.ComponentModel.DataAnnotations assembly(dll)

1) Make sure to add a reference to System.ComponentModel.DataAnnotations assembly(dll)

2) Add a using statement to import the System.ComponentModel.DataAnnotations namespace in your class file.

using System.ComponentModel.DataAnnotations;
public class YourModel
{
  [Required]
  public string Name {set;get;}
}