How to call a SOAP web service in .NET 4.0 C# without using the WSDL or proxy classes

If you want to call a .NET 4.0 C# web service, without using the WSDL or “Add Service Reference” in Microsoft Visual Studio 2010. You can use the following functions:

/// <summary>
/// Execute a Soap WebService call
/// </summary>
public override void Execute()
{
    HttpWebRequest request = CreateWebRequest();
    XmlDocument soapEnvelopeXml = new XmlDocument();
    soapEnvelopeXml.LoadXml(@"<?xml version=""1.0"" encoding=""utf-8""?>
<soap:Envelope xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/"" xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"">
<soap:Body>
    <HelloWorld3 xmlns=""http://tempuri.org/"">
        <parameter1>test</parameter1>
        <parameter2>23</parameter2>
        <parameter3>test</parameter3>
    </HelloWorld3>
</soap:Body>
</soap:Envelope>");

    using (Stream stream = request.GetRequestStream())
    {
        soapEnvelopeXml.Save(stream);
    }

    using (WebResponse response = request.GetResponse())
    {
        using (StreamReader rd = new StreamReader(response.GetResponseStream()))
        {
            string soapResult = rd.ReadToEnd();
            Console.WriteLine(soapResult);
        }
    }
}
/// <summary>
/// Create a soap webrequest to [Url]
/// </summary>
/// <returns></returns>
public HttpWebRequest CreateWebRequest()
{
    HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(@"http://dev.nl/Rvl.Demo.TestWcfServiceApplication/SoapWebService.asmx");
    webRequest.Headers.Add(@"SOAP:Action");
    webRequest.ContentType = "text/xml;charset=\"utf-8\"";
    webRequest.Accept = "text/xml";
    webRequest.Method = "POST";
    return webRequest;
}

Result
<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><HelloWorld3Response xmlns="http://tempuri.org/"><HelloWorld3Result>test</HelloWorld3Result></HelloWorld3Response></soap:Body></soap:Envelope>

You can use complex types in you’re request. I use fiddler to get the contents of the soap envelope.