Why can't I do like this?
[Required(ErrorMessage = "*")]
[RegularExpression("^[a-zA-Z0-9_]*$", ErrorMessage = Resources.RegistrationModel.UsernameError)]
public string Username { get; set; }
What is the error message telling me?
An attribute argument must be a
constant expression , typeof
expression or array creation
expression of an attribute parameter
type.
Best Answer
When you are using the
ErrorMessage
property only constant strings or string literal can be assigned to it.Use the
ErrorMessageResourceType
andErrorMessageResourceName
instead to specity your resources.Note that the resources must be public (can be set in the resource editor).