ASP.NET MVC F# controller action ignoring parameter

Posted by Matt H on Stack Overflow See other posts from Stack Overflow or by Matt H
Published on 2010-05-03T01:01:58Z Indexed on 2010/05/03 1:08 UTC
Read the original article Hit count: 380

Filed under:

F#

|

ASP.NET

|

mvc

|

.NET

|

c#

Hi.

I have a C# ASP.NET MVC project but my controllers are written in F#.

For some reason, the following code doesn't work properly.

namespace MvcApplication8.Controllers

open System.Web.Mvc

[<HandleError>]
type ImageController() =
  inherit Controller()

  member x.Index (i : int) : ActionResult =
    x.Response.Write i
    x.View() :> ActionResult

The parameter of the action is seemingly ignored.

http://localhost:56631/Image/Index/1

=>

The parameters dictionary contains a null entry for parameter 'i' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult Index(Int32)' in 'MvcApplication8.Controllers.ImageController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
Parameter name: parameters

The controller otherwise works fine. I know that plenty of people have written F# mvc code, so, any ideas where I'm going wrong?

© Stack Overflow or respective owner

Related posts about F#

FSharp.Core.sigdata not found alongside FSharp.Core

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm trying to use F# for an ASP.NET MVC application. One my controller actions sends an F# list to the view, so I write: <%@ Page Language="C#" Inherits="ViewPage<FSharpList<int>>" %> Of course, for this to work, I have to add Microsoft.FSharp.Collections to the namespaces element… >>> More
F# Powerpack's Metadata doesn't recognize FSharp.Core as an F# library

as seen on Stack Overflow - Search for 'Stack Overflow'
Here's my test code to isolate the problem: open Microsoft.FSharp.Metadata [<EntryPoint>] let main args = let core = FSharpAssembly.FromFile @"C:\Program Files\FSharp-2.0.0.0\\bin\FSharp.Core.dll" let core2 = FSharpAssembly.FSharpLibrary let core3 = System.AppDomain.CurrentDomain.GetAssemblies()… >>> More
Nasty mono bug with F#

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I have this monstrous f# 2.0 program My mono version is Mono JIT compiler version 2.9 (master/f593354 Sun Dec 26 03:15:55 EET 2010) Copyright (C) 2002-2010 Novell, Inc and Contributors. www.mono-project.com TLS: __thread SIGSEGV: altstack Notifications: epoll Architecture:… >>> More
Could not load file or assembly FSharp.Core, Version=4.0.0.0

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm trying to deploy a web application which uses F# 4.0 on Windows Server 2008. It works on my computer where VS2010 is installed but it doesn't work on the server. Everytime you open the page you'll get this error message: Could not load file or assembly 'FSharp.Core, Version=4.0.0.0, Culture=neutral… >>> More
FSharp.Compiler.CodeDom for VS2008 and VS2010 side-by-side

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm using FSharp.Compiler.CodeDom to dynamically create F# classes. The problem is, that I have both VS2008 and VS2010 on my computer side-by-side (they works fine), and using F# in this configuration is buggy at best: If I don't install InstallFSharp.msi, then under VS2008 the built classes complain… >>> More

Related posts about ASP.NET

Migrating ASP.NET MVC 1.0 applications to ASP.NET MVC 2 RTM

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Note: ASP.NET MVC 2 RTM isn’t yet released! But this tool will help you get your ASP.NET MVC 1.0 applications ready for when it is! I have updated the MVC App Converter to convert projects from ASP.NET MVC 1.0 to ASP.NET MVC 2 RTM. This should be last the last major change to the MVC App Converter… >>> More
April 14th Links: ASP.NET, ASP.NET MVC, ASP.NET Web API and Visual Studio

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Here is the latest in my link-listing blog series: ASP.NET Easily overlooked features in VS 11 Express for Web: Good post by Scott Hanselman that highlights a bunch of easily overlooked improvements that are coming to VS 11 (and specifically the free express editions) for web development: unit… >>> More
Use ASP.NET 4 Browser Definitions with ASP.NET 3.5

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
We updated the browser definitions files included with ASP.NET 4 to include information on recent browsers and devices such as Google Chrome and the iPhone. You can use these browser definition files with earlier versions of ASP.NET such as ASP.NET 3 Read More......(read more) >>> More
ASP.NET webforms + ASP.NET Ajax versus ASP.NET MVC and Ajax framework freedom

as seen on Stack Overflow - Search for 'Stack Overflow'
If given the choice, which path would you take? ASP.NET Webforms + ASP.NET AJAX or ASP.NET MVC + JavaScript Framework of your Choice Are there any limitations that ASP.NET Webforms / ASP.NET AJAX has vis-a-vis MVC? >>> More
ASP.NET MVC 2 Released

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
I’m happy to announce that the final release of ASP.NET MVC 2 is now available for VS 2008/Visual Web Developer 2008 Express with ASP.NET 3.5. You can download and install it from the following locations: Download ASP.NET MVC 2 using the Microsoft Web Platform Installer Download… >>> More