Why can't I use resources as ErrorMessage with DataAnnotations?

Question

Why can\'t I do like this?

[Required(ErrorMessage = \"*\")]
[RegularExpression(\"^[a-zA-Z0-9_]*$\", ErrorMessage = Resources.RegistrationModel.UsernameError)         


        

Answer 1

We can now use nameof for strongly typed error messages:

[RegularExpression("^[a-zA-Z0-9_]*$", 
  ErrorMessageResourceType=typeof(Resources.RegistrationModel),
  ErrorMessageResourceName=nameof(Resources.RegistrationModel.UsernameError)
)]