I have an action that looks like

public ActionResult GetUsers(List<int> userIds) {//do stuff}

The list of userIds can become quite long, so I want to use Json.Net to deserialize it. To do so I created an IModelBinder implementation, which works fine for other objects, but never gets called for a List. The IModelBind looks like this

public class JsonBinder : System.Web.Mvc.IModelBinder
{
  public object BindModel(System.Web.Mvc.ControllerContext controllerContext, System.Web.Mvc.ModelBindingContext bindingContext)
  { //Do model binding stuff using Json.Net }
} 

And I register this model binder with this line

ModelBinders.Binders.Add(typeof(List<int>), new JsonBinder());

However the JsonBinder is never called. Why is this? Should I be using a ValueProvider?