Question

Lets say I have these class

public class BaseClass
{
  public int Id { get; set; }
}

and

public class SomeClass : BaseClass
{
  ... more properties ...
}

BaseClass is considered to be used on a lot of places.

In my case I’m using ASP.NET MVC 3’s EditorForModel to render Views, and it’s common to decorate properties with attributes such as [Display(Name = "Id"), Required]

But lets say I would want to decorate the properties of BaseClass in different ways for every class that inherits it. In SomeClass I may want to decorate Id with [Required] and in OtherClass I might want to decorate it with [SomeCustomAttribute].

Is there a way to this?

It would be nice to be able to do something like this:

public class SomeClass : BaseClass
{
  public SomeClass()
  {
    WithProperty(x => x.Id).AddAttribute(new RequiredAttribute());
    ...
  }

  ... more properties ...
}

Answer 1

Attributes are static metadata. Assemblies, modules, types, members, parameters, and return values aren’t first-class objects in C# (e.g., the System.Type class is merely a reflected representation of a type). You can get an instance of an attribute for a type and change the properties if they’re writable but that won’t affect the attribute as it is applied to the type