VB.net中的ASP.net MVC HtmlHelper

Question

stupid question here. I'm trying to create a helper method, something similar to the radio button list in the MVC futures project (as a learning tool).

I'm trying to convert the C# code:

 public static string[] RadioButtonList(this HtmlHelper htmlHelper, string name, IDictionary<string, object> htmlAttributes) {

to a method signature in VB.net, but I'm not sure how to write the first parameter in VB.net, or what you would call this, so I could look it up?

Answer 1

I'm not either. But this is the signature of an extension method. Here's the MSDN docs on doing this in VB.

Answer 2

I believe this will work as long as you remember to mark it as an extension method, you could look up Extension Methods on MSDN.com . They have examples of how to write extension methods in VB.net.

<System.Runtime.CompilerServices.Extension> _
Public Shared Function RadioButtonList(ByVal htmlHelper As HtmlHelper, ByVal name As String, ByVal htmlAttributes As IDictionary(Of String, Object)) As String()
    
End Function

Answer 3

They are called Extension methods , and are declared in VB.Net like this:

<System.Runtime.CompilerServices.Extension()> _
Public Sub RadioButtonList(ByVal name As String, ...)
// There's no "this" parameter at all...

Answer 4

Extension methods in VB can only be declared from within a module, not a class, so a complete skeleton definition would look something like this...

Imports System.Web.Mvc

Public Module MyModule

    <System.Runtime.CompilerServices.Extension> _
    Public Function MyHelper (ByVal helper As HtmlHelper, MyParameter as String) As String

    End Function

End Module