Question

I have found 4 or 5 examples of “lowercase routes” in C# however when I use the telerik code converter, I get a bunch of errors.

Namely something to do with "extension methods can be defined only in modules."

Does anyone have any good resources on how to map routes to lowercase in VB?

EDIT:

here is an example of some converted code that is erroring

Imports System
Imports System.Web.Mvc
Imports System.Web.Routing

Namespace MyMvcApplication.App.Helpers
    Public Class LowercaseRoute
        Inherits System.Web.Routing.Route
        Public Sub New(ByVal url As String, ByVal routeHandler As IRouteHandler)
            MyBase.New(url, routeHandler)
        End Sub
        Public Sub New(ByVal url As String, ByVal defaults As RouteValueDictionary, ByVal routeHandler As IRouteHandler)
            MyBase.New(url, defaults, routeHandler)
        End Sub
        Public Sub New(ByVal url As String, ByVal defaults As RouteValueDictionary, ByVal constraints As RouteValueDictionary, ByVal routeHandler As IRouteHandler)
            MyBase.New(url, defaults, constraints, routeHandler)
        End Sub
        Public Sub New(ByVal url As String, ByVal defaults As RouteValueDictionary, ByVal constraints As RouteValueDictionary, ByVal dataTokens As RouteValueDictionary, ByVal routeHandler As IRouteHandler)
            MyBase.New(url, defaults, constraints, dataTokens, routeHandler)
        End Sub

        Public Overrides Function GetVirtualPath(ByVal requestContext As RequestContext, ByVal values As RouteValueDictionary) As VirtualPathData
            Dim path As VirtualPathData = MyBase.GetVirtualPath(requestContext, values)

            If path IsNot Nothing Then
                path.VirtualPath = path.VirtualPath.ToLowerInvariant()
            End If

            Return path
        End Function
    End Class

    Public NotInheritable Class RouteCollectionExtensions
        Private Sub New()
        End Sub
        <System.Runtime.CompilerServices.Extension()> _
        Public Shared Sub MapRouteLowercase(ByVal routes As RouteCollection, ByVal name As String, ByVal url As String, ByVal defaults As Object)
            routes.MapRouteLowercase(name, url, defaults, Nothing)
        End Sub

        <System.Runtime.CompilerServices.Extension()> _
        Public Shared Sub MapRouteLowercase(ByVal routes As RouteCollection, ByVal name As String, ByVal url As String, ByVal defaults As Object, ByVal constraints As Object)
            If routes Is Nothing Then
                Throw New ArgumentNullException("routes")
            End If

            If url Is Nothing Then
                Throw New ArgumentNullException("url")
            End If

            Dim route = New LowercaseRoute(url, New MvcRouteHandler()) With { _
             .Defaults = New RouteValueDictionary(defaults), _
             .Constraints = New RouteValueDictionary(constraints) _
            }

            If [String].IsNullOrEmpty(name) Then
                routes.Add(route)
            Else
                routes.Add(name, route)
            End If
        End Sub
    End Class
End Namespace

Answer 1

To solve your “extension methods can be defined only in modules.” problem:
Change “NotInheritable class” where you defined those methods to “Module” and remove the constructor.