I'm trying to convert this code to VB.NET:

public static void Main(string[] args)
    {
        var myProxy = new WebProxy("http://proxy.zyte.com:8011", true);
        myProxy.Credentials = new NetworkCredential("<CRAWLERA_APIKEY>", "");

        var request = (HttpWebRequest)WebRequest.Create("https://httpbin.scrapinghub.com/headers");
        request.Proxy = myProxy;
        request.PreAuthenticate = true;
        request.AllowAutoRedirect = false;
        request.ServerCertificateValidationCallback  = (sender, certificate, chain, sslPolicyErrors) => true;

        var response = request.GetResponse();
        Console.WriteLine("Response Status: "   ((HttpWebResponse)response).StatusDescription);
        Console.WriteLine("\nResponse Headers:\n"   ((HttpWebResponse)response).Headers);
        var dataStream = response.GetResponseStream();
        var reader = new StreamReader(dataStream);
        string responseFromServer = reader.ReadToEnd();
        Console.WriteLine("Response Body:\n"   responseFromServer);
        reader.Close();
        response.Close();
    }

What I have so far is:

Public Shared Sub Main(ByVal args As String())
        Dim myProxy = New WebProxy("http://proxy.zyte.com:8011", True)
        myProxy.Credentials = New NetworkCredential("<CRAWLERA_APIKEY>", "")
        Dim request = CType(WebRequest.Create("https://httpbin.scrapinghub.com/headers"), HttpWebRequest)
        request.Proxy = myProxy
        request.PreAuthenticate = True
        request.AllowAutoRedirect = False
        AddHandler request.ServerCertificateValidationCallback, Function(sender, certificate, chain, sslPolicyErrors) True
        Dim response = request.GetResponse()
        Console.WriteLine("Response Status: " & (CType(response, HttpWebResponse)).StatusDescription)
        Console.WriteLine(vbLf & "Response Headers:" & vbLf & (CType(response, HttpWebResponse)).Headers)
        Dim dataStream = response.GetResponseStream()
        Dim reader = New StreamReader(dataStream)
        Dim responseFromServer As String = reader.ReadToEnd()
        Console.WriteLine("Response Body:" & vbLf & responseFromServer)
        reader.Close()
        response.Close()
    End Sub

This fails on line: AddHandler request.ServerCertificateValidationCallback, Function(sender, certificate, chain, sslPolicyErrors) True Where I get error

'ServerCertificateValidationCallback' is not an event of 'HttpWebRequest'.

I'm not sure how to translate it.

CodePudding user response：

As the error message says, that member is not an event, so you cannot handle it. It's a property, so you have to assign to it like any other property. It's type is RemoteCertificateValidationCallback, which is a delegate, i.e. an object that refers to a method. You need to create a delegate of that type and assign it to the property:

request.ServerCertificateValidationCallback = Function(sender, certificate, chain, sslPolicyErrors) True