[VB.Net] Abilitare CORS

[Kahm]

premetto che Ho fatto una ricerca, ed ho letto numerosi thread, risultato: mi arrendo!
Ho un sito web con framework 4, ma è un semplice webForm

1) ho scaricato e referenziato le DLL System.Web.Cors, system.web.http.Cors

2) ho implementato il beginRequest in Global.asax

  Sub Application_BeginRequest(ByVal sender As Object, ByVal e As EventArgs)

        Dim Context = HttpContext.Current
        Dim Response = Context.Response
        Dim Config As System.Web.Http.HttpConfiguration

        Dim Cors As New EnableCorsAttribute("*", "*", "*")

        ' enable CORS  
        Response.AddHeader("Access-Control-Allow-Origin", "*")
        Response.AddHeader("X-Frame-Options", "ALLOW-FROM *")

        If (Context.Request.HttpMethod = "OPTIONS") Then
            Response.AddHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
            Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept")
            Response.End()
        End If
    End Sub

3) ho aggiunto i riferimenti in web.config riguardo il Cors

<system.webServer>
    <httpProtocol>
      <customHeaders>
        <add name="Access-Control-Allow-Origin" value="*" />
        <add name="Access-Control-Allow-Methods" value="GET,POST,OPTIONS,PUT,DELETE" />
        <add name="Access-Control-Allow-Headers" value="Content-Type,soapaction" />
      </customHeaders>
    </httpProtocol>
  </system.webServer>
<system.webServer xmlns="">
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
  </system.webServer>
  <runtime xmlns="">
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-9.0.0.0" newVersion="9.0.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>

4) nel servizio web ho aggiunto i riferimenti al CORS, sia nella dichiarazione di classe che nel metodo

  
<EnableCors("*", "*", "*")>
<Route("api/sendrequest")>
<System.Web.Script.Services.ScriptService()>
<WebService(Namespace:="http://tempuri.org/")>
<WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)>
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()>
Public Class PetService
    Inherits System.Web.Services.WebService

    <EnableCors("*", "*", "*")>
    <WebMethod>
    Public Function Login(user As String, pass As String) As Boolean
    ............

in tutti gli esempi che leggo basta una sola implementazione, BOH
non so cosa dire o fare