I am trying to get my URLs in files/id format. I am guessing I should have two Index methods in my controller, one with a parameter and one with not. But I get this error message in browser below.

Anyway here is my controller methods:

public ActionResult Index()
        {
            return Content("Index ");
        }

        //
        // GET: /Files/5
        public ActionResult Index(int id)
        {
            File file = fileRepository.GetFile(id);
            if (file == null) return Content("Not Found");
            else return Content(file.FileID.ToString());
        }

Error:

Server Error in '/' Application.

The current request for action 'Index' on controller type 'FilesController' is ambiguous between the following action methods: System.Web.Mvc.ActionResult Index() on type FileHosting.Controllers.FilesController System.Web.Mvc.ActionResult Index(Int32) on type FileHosting.Controllers.FilesController

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Reflection.AmbiguousMatchException: The current request for action 'Index' on controller type 'FilesController' is ambiguous between the following action methods: System.Web.Mvc.ActionResult Index() on type FileHosting.Controllers.FilesController System.Web.Mvc.ActionResult Index(Int32) on type FileHosting.Controllers.FilesController

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[AmbiguousMatchException: The current request for action 'Index' on controller type 'FilesController' is ambiguous between the following action methods: System.Web.Mvc.ActionResult Index() on type FileHosting.Controllers.FilesController System.Web.Mvc.ActionResult Index(Int32) on type FileHosting.Controllers.FilesController] System.Web.Mvc.ActionMethodSelector.FindActionMethod(ControllerContext controllerContext, String actionName) +396292 System.Web.Mvc.ReflectedControllerDescriptor.FindAction(ControllerContext controllerContext, String actionName) +62 System.Web.Mvc.ControllerActionInvoker.FindAction(ControllerContext controllerContext, ControllerDescriptor controllerDescriptor, String actionName) +13 System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +99 System.Web.Mvc.Controller.ExecuteCore() +105 System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +39 System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +7 System.Web.Mvc.<>c_DisplayClass8.b_4() +34 System.Web.Mvc.Async.<>c_DisplayClass1.b_0() +21 System.Web.Mvc.Async.<>c__DisplayClass81.<BeginSynchronous>b__7(IAsyncResult _) +12 System.Web.Mvc.Async.WrappedAsyncResult1.End() +59 System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +44 System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +7 System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8677678 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

Updated Code:

public ActionResult Index(int? id)
        {
            if (id.HasValue)
            {
                File file = fileRepository.GetFile(id.Value);
                if (file == null) return Content("Not Found");
                else return Content(file.FileID.ToString());
            }
            else
                return Content("Index");
        }

It's still not the thing I want. URLs have to be in files?id=3 format. I want files/3

routes from global.asax

routes.MapRoute(
                "Default", // Route name
                "{controller}/{action}/{id}", // URL with parameters
                new { controller = "Home", action = "Index", 
                id = UrlParameter.Optional } // Parameter defaults
            );
            //files/3
            //it's the one I wrote
            routes.MapRoute("Files", "{controller}/{id}", 
            new { controller = "Files", action = "Index", id = UrlParameter.Optional}
            );

I tried adding a new route after reading Jeff's post but I can't get it working. It still works with files?id=2 though.