Question

Wondering if this is possible or something with this effect.

public class MyModel
{
    public string Name { get; set; }

    [Display(Name = String.Format("This is [0]'s phone number", Name)]
    public string PhoneNumber { get; set; }
}

I’m talking about a DisplayName with a variable in it, non static and possibly based on the models other properties. Is this possible in any way?

Answer 1

This isn’t possible because the arguments specified for parameters of attributes must be constant values (instinctively, because there is no context in relation to anything else and not necessarily able to be resolved at compile-time (which is a requirement)). From the C# Specification (3.0) §17.2:

An expression E is an attribute-argument-expression if all of the following statements are true:

• The type of E is an attribute parameter type (§17.1.3).
• At compile-time, the value of E can be resolved to one of the following:
  • A constant value.
  • A System.Type object.
  • A one-dimensional array of attribute-argument-expressions.