I came across this problem where I had a basic list of items and for each if these items I wanted to add a delete action on my controller. I wanted to add some error checking around the delete action so if someone attempted to modify the URL and enter a incorrect parameter into my controller, I wanted to redirect back to the previous controller and notify the user of this mistake. Take this example. I have a Product Controller and the Index Action and View lists all of the products. I have a delete action on the Product Controller which checks if the productId parameter is valid and then removes the product and redirects to the Index action using the RedirectToAction method.

The solution

When validating the productId, if its NOT valid simply add a new key/value to the TempData object and call the RedirectToAction method. TempData stores data for short periods of time for the current and next HTTP request. In your index view, you can check to see if your key/value pair exists and display a error message. If you refresh the page, you will notice the data from the TempData will be gone. Remember to use RedirectToAction where possible as this is more friendly with Unit Testing rather than using the HttpResponse redirect method.

This reference illustrates a good understanding between TempData, ViewBag and ViewData.

http://rachelappel.com/when-to-use-viewbag-viewdata-or-tempdata-in-asp.net-mvc-3-applications

Credit to Steve Testa, Thanks!.

Compiler Error Message: CS1973: ‘System.Web.Mvc.HtmlHelper’ has no applicable method named ‘Render’ but appears to have an extension method by that name. Extension methods cannot be dynamically dispatched. Consider casting the dynamic arguments or calling the extension method without the extension method syntax.

The issue was that the compiler could not choose the correct method because my model was “dynamic”.

The correct syntax is:

Origional file:

public class GlobalApplication : System.Web.HttpApplication

 {

 public static void RegisterRoutes(RouteCollection routes)           {                routes.IgnoreRoute("{resource}.axd/{*pathInfo}");                routes.MapRoute(                     "Default",// Route name                     "{controller}/{action}/{id}",// URL with parameters                     new { controller = "Home", action = "Index", id = "" }                           // Parameter defaults                );

 }

 protected void Application_Start()

 {

 RegisterRoutes(RouteTable.Routes);

 }

 }

Change to the following:

public class GlobalApplication : System.Web.HttpApplication

 {

 public static void RegisterRoutes(RouteCollection routes)           {                routes.IgnoreRoute("{resource}.axd/{*pathInfo}");                routes.MapRoute(                     "Default",// Route name                     "{controller}.aspx/{action}/{id}",// URL with parameters                     new { controller = "Home", action = "Index", id = "" }                           // Parameter defaults                );

 }

 protected void Application_Start()

 {

 RegisterRoutes(RouteTable.Routes);

 }

 }

Just add the .aspx extension so that it registers through the .NET Framework.

ALSO remember to do a Response.Redirect in the default.aspx page so that the first page will be your default URL routing page, otherwise you will receive a HttpException “The incoming request does not match any route.”.