title: How do you use the new ModelBinder classes in ASP.NET MVC Preview 5
body: <p>You'll notice that Preview 5 includes the following in their release notes:</p>
  
  <blockquote>
    <p>Added support for custom model binders. Custom binders allow you to define complex types as parameters to an action method. To use this feature, mark the complex type or the parameter declaration with [ModelBinder(…)].</p>
  </blockquote>
  
  <p>So how do you go about actually using this facility so that I can have something like this work in my Controller:</p>
  
  <pre><code>public ActionResult Insert(Contact contact)
  {
      if (this.ViewData.ModelState.IsValid)
      {
          this.contactService.SaveContact(contact);
  
          return this.RedirectToAction("Details", new { id = contact.ID}
      }
  }
  </code></pre>