{
            var postData = @"
<soapenv:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" xmlns:soapenv=""http://schemas.xmlsoap.org/soap/envelope/"" xmlns:api=""API"">
   <soapenv:Header/>
   <soapenv:Body>
      <api:listGoods soapenv:encodingStyle=""http://schemas.xmlsoap.org/soap/encoding/"">
         <login xsi:type=""xsd:string"">109185_bondarchuk</login>
         <pass xsi:type=""xsd:string"">XPzxmgEG9A</pass>
         <art xsi:type=""xsd:string"">QF36A00199</art>
         <cross xsi:type=""xsd:integer""></cross>
         <br xsi:type=""xsd:string""></br>
      </api:listGoods>
   </soapenv:Body>
</soapenv:Envelope>";


            using (var httpClient = new HttpClient())
            {
                httpClient.BaseAddress = new Uri("https://api.forum-auto.ru");

                var content = new StringContent(postData);
                content.Headers.ContentType = new MediaTypeHeaderValue("text/xml");
                content.Headers.Add("SOAPAction", "listGoods");

                var postAsync = httpClient.PostAsync("/soap", content);
                var resultContent = postAsync.Result.Content.ReadAsStringAsync().Result;
            }

            //            HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("https://api.forum-auto.ru/soap");
            //            req.Method = "POST";
            //            req.Timeout = 60000;
            //            req.ContentType = "text/xml;charset=UTF-8";
            //            req.Headers.Add("SOAPAction", "listGoods");
            //
            //            byte[] m = Encoding.ASCII.GetBytes(postData);
            //            req.GetRequestStream().Write(m, 0, postData.Length);
            //
            //
            //            string resp = "";
            //            using (var WebResponse = (HttpWebResponse)req.GetResponse())
            //            {
            //                using (var stream = WebResponse.GetResponseStream())
            //                {
            //                    using (var reader = new StreamReader(stream, Encoding.GetEncoding(WebResponse.CharacterSet)))
            //                    {
            //                        resp = reader.ReadToEnd();
            //                    }
            //                }
            //            }
        }