Up until SlickUpload 5.5, the ASP.NET MVC examples demonstrated calling the SlickUpload.GetUploadStatus() method in your action method to get the current upload status. This isn't the optimal way to get access to upload status and uploaded files in your action method -- it violates the idea of separation of concerns that MVC is built upon.

Fortunately, the fix is easy -- create and register a custom ModelBinder that maps the UploadStatus into a parameter for your action method. The model binder is simple:

using System;
using System.Web;
using System.Web.Mvc;

using Krystalware.SlickUpload;
using Krystalware.SlickUpload.Controls;
using Krystalware.SlickUpload.Status;

public class UploadStatusModelBinder : IModelBinder
{
    public static void Register(ModelBinderDictionary modelBinders)
    {
        if (!modelBinders.ContainsKey(typeof(UploadStatus)))
            modelBinders.Add(typeof(UploadStatus), new UploadStatusModelBinder());
    }

    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        UploadStatus status = HttpUploadModule.GetUploadStatus() ?? UploadConnector.GetUploadStatus();

        return status;
    }
}

The Register method manages registering this class in ASP.NET MVC's model binder lookup. Call it from your Application_Start, the same place where you register routes. Something like:

protected void Application_Start()
{
    RegisterRoutes(RouteTable.Routes);

    UploadStatusModelBinder.Register(ModelBinders.Binders);
}

The BindModel method does the actual binding. The logic pulls the UploadStatus for the current context, and if that isn't available checks to see if this is a SlickUpload based after upload postback and returns the UploadStatus for that. If it's neither, the parameter will recieve null.

So, your MVC controller action method changes from this:

public ActionResult UploadResult()
{
    UploadStatus status = SlickUpload.GetUploadStatus();

    // controller logic

    return View(status);
}

To this:

public ActionResult UploadResult(UploadStatus status)
{
    // controller logic

    return View(status);
}