I am running DNN7.02 and am trying to create a WebAPI service, following the example in this blog entry: http://www.dotnetnuke.com/Resources/Blogs/EntryId/3500/Getting-Started-with-Services-Framework-WebAPI-Edition.aspx.  I am writing mine in VB instead of C#, but otherwise I have followed the example exactly.  When I build the class library my dll shows up in the bin directory of my DNN site.  So far so good.  When I go to the URL that I believe should evoke my function I get an error message that says "Unable to locate a controller for http://dnndev.me/desktopmodules/MyServices/API/welcome/HelloWorld. Searched in namespaces: MyServices."  

Here is my code:

Imports System
Imports System.Net
Imports System.Net.Http
Imports System.Web.Http
Imports DotNetNuke.Web.Api

Namespace MyServices

    Public Class WelcomeController
        Inherits DnnApiController
        Implements IServiceRouteMapper

        <AllowAnonymous()> _
        <HttpGet()> _
        Public Function HelloWorld() As HttpResponseMessage
            Return Request.CreateResponse(HttpStatusCode.OK, "Hello World!")
        End Function

        Public Sub RegisterRoutes(mapRouteManager As IMapRoute) Implements IServiceRouteMapper.RegisterRoutes
            mapRouteManager.MapHttpRoute("MyServices", "default", "{controller}/{action}", New String() {"MyServices"})
        End Sub

    End Class

End Namespace

I am going to the URL http://dnndev.me/desktopmodules/MyServices/API/welcome/HelloWorld.

Any ideas what I am doing wrong?  

That fixed it!  You are the man.  Thank you so much.

Hello!
I tried the example as a class project in VBnet too and it works after making the changes mentioned above, it works as expected .. thanks a lot for the tip with the Namespace!

Now I wanted to add a service to my own module that is based on the christoc VB2012 template for VB.
I added a class "WSController to the Project Directory, at the same level as view.ascx etc and added the code above

First when trying to call the Service from the browser i got a message about a missing dll
(Could not load file or assembly 'FiftyOne.Foundation' or one of its dependencies." ... I decided to solve it quick and very dirty and added a reference to that dll in dnns bin folder ...

Now when I try to access the Service by calling:
http://localhost/dnn7/DesktopModules/myModule/API/WS/HelloWorld
it produces the following Error:

Object reference not set to an instance of an object.

Stack Trace: 

[NullReferenceException: Object reference not set to an instance of an object.] DotNetNuke.Common.Globals.get_Status() +158 DotNetNuke.HttpModules.RewriterUtils.OmitFromRewriteProcessing(String localPath) +55 DotNetNuke.HttpModules.RequestFilter.RequestFilterModule.FilterRequest(Object sender, EventArgs e) +205 System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +79 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +164 

please can anybody assist to sort out what the problem may be?

In the Project Properties I have already tried to remove the base Namespace (mmm.Modules.mmmModule1)  and adding it to the file "WSController" wrapping the Class "WSController" with no success.

The module is set up in localhost/dnn7/DesktopModules/mmmModule1
In this Folder there lies the Class "WSController.vb" with the following code:

Imports System
Imports System.Net
Imports System.Net.Http
Imports System.Web.Http
Imports DotNetNuke.Web.Api

Public Class WSController
    Inherits DnnApiController
    Implements IServiceRouteMapper

    <DnnAuthorize()> _
    <HttpGet()> _
    Public Function HelloWorld() As HttpResponseMessage
            Return Request.CreateResponse(HttpStatusCode.OK, "Hello World!")
    End Function

    ' Route Mapper
    Public Sub RegisterRoutes(mapRouteManager As IMapRoute) Implements IServiceRouteMapper.RegisterRoutes
        mapRouteManager.MapHttpRoute("mmmModule1", "default", "{controller}/{action}", New String() {"mmmModule1"})
    End Sub

End Class

Thanks in advance for any hint that puts me back on the road ;-)
kind regards
Don