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

You should instead look at the ErrorMessageResourceName and ErrorMessageResourceType properties of this attribute. They do allow the error message to be pulled from a resource.