Imports System
Imports System.IO
Imports System.Net
Imports System.Text
Namespace Examples.System.Net
    Public Class WebRequestPostExample

        Public Shared Sub Main()
            ' Create a request using a URL that can receive a post. 
            Dim request As WebRequest = WebRequest.Create("http://www.contoso.com/PostAccepter.aspx ")
            ' Set the Method property of the request to POST.
            request.Method = "POST"
            ' Create POST data and convert it to a byte array.
            Dim postData As String = "This is a test that posts this string to a Web server."
            Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
            ' Set the ContentType property of the WebRequest.
            request.ContentType = "application/x-www-form-urlencoded"
            ' Set the ContentLength property of the WebRequest.
            request.ContentLength = byteArray.Length
            ' Get the request stream.
            Dim dataStream As Stream = request.GetRequestStream()
            ' Write the data to the request stream.
            dataStream.Write(byteArray, 0, byteArray.Length)
            ' Close the Stream object.
            dataStream.Close()
            ' Get the response.
            Dim response As WebResponse = request.GetResponse()
            ' Display the status.
            Console.WriteLine(CType(response, HttpWebResponse).StatusDescription)
            ' Get the stream containing content returned by the server.
            dataStream = response.GetResponseStream()
            ' Open the stream using a StreamReader for easy access.
            Dim reader As New StreamReader(dataStream)
            ' Read the content.
            Dim responseFromServer As String = reader.ReadToEnd()
            ' Display the content.
            Console.WriteLine(responseFromServer)
            ' Clean up the streams.
            reader.Close()
            dataStream.Close()
            response.Close()
        End Sub
    End Class
End Namespace

public static string HttpPost(string URI, string Parameters) 
{
   System.Net.WebRequest req = System.Net.WebRequest.Create(URI);
   req.Proxy = new System.Net.WebProxy(ProxyString, true);
   // 竟然我们是要发送 POST
   req.ContentType = "application/x-www-form-urlencoded";
   req.Method = "POST";
   // 我们必须知道我们要发送多少 bytes. 
   // Post'ed Faked Forms should be name=value&
   byte [] bytes = System.Text.Encoding.ASCII.GetBytes(Parameters);
   req.ContentLength = bytes.Length;
   System.IO.Stream os = req.GetRequestStream ();
   os.Write (bytes, 0, bytes.Length); //Push it out there
   os.Close ();
   System.Net.WebResponse resp = req.GetResponse();
   if (resp== null) return null;
   System.IO.StreamReader sr = 
         new System.IO.StreamReader(resp.GetResponseStream());
   return sr.ReadToEnd().Trim();
}