Dependency Injection on the AuthorizationFilterAttribute

I'm new to Unity and IoC in general and as usual I quickly got into the binding ...

I created an Authorization Filter Attribute for the ASP.NET Web API Beta. Now I need to inject my authorizer into an attribute, but since it is an attribute, I can't just do it public TestAuthAttribute(IAuthorizer Authorizer)

in my constructor.

So, I decided to create a public property decorated with a [Dependency] attribute to inject properties, however it will not be allowed.

Here is the code:

public class TestAuthAttribute : AuthorizationFilterAttribute
{
    [Dependency]
    public IAuthorizer Authorizer { get; set; }

    public TestAuthAttribute() {
        ...
        }

    private bool authorizeCore(HttpRequestMessage request)
    {
        if (Authorizer == null)
            throw Error.ArgumentNull("Null Authorizer");  // <<<<< this is null
    }

      

        
        
        
      

    

When the controller is decorated with [TestAuth], the Attribute is fired, but the authorizer is not allowed, it is zero)

I put the following code in my controller and the authorizer allowed ...

[Dependency]
    public IAuthorizer Authorizer { get; set; }

      

        
        
        
      

    

Why is this dependency not resolved in my AuthorizationFilterAttribute and how would you go about it? Entering an authorizer into the AuthorizationFilterAttribute?