国外某牛人的JsonModelBinder 实现 MVC 3.0

public class JsonModelBinder : DefaultModelBinder
     {
         public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
         {

             if (!IsJSONRequest(controllerContext))
             {
                 return base.BindModel(controllerContext, bindingContext);
             }

             // Get the JSON data that's been posted
             var request = controllerContext.HttpContext.Request;
             var jsonStringData = new StreamReader(request.InputStream).ReadToEnd();
                return new JavaScriptSerializer().Deserialize(jsonStringData, bindingContext.ModelMetadata.ModelType);

         }

         private static bool IsJSONRequest(ControllerContext controllerContext)
         {
             var contentType = controllerContext.HttpContext.Request.ContentType;
             return contentType.Contains("FTchinaMVC/json");
         }
     }

protected void Application_Start()
        {
            ModelBinders.Binders.DefaultBinder = new JsonModelBinder();
            RegisterRoutes(RouteTable.Routes);
        }
            AreaRegistration.RegisterAllAreas();

            RegisterGlobalFilters(GlobalFilters.Filters);

http://www.cnblogs.com/zihuxinyu/articles/extjs_jsonmodelbinder_mvc3_ajax.html