gistfile1.cs

            HtmlString = HtmlString.Replace("&", "__amp__");
            String _postData = String.Format("data={0}", HtmlString);
 
            System.Text.Encoding encoding = new System.Text.UTF8Encoding();
            byte[] _data = encoding.GetBytes(_postData);
 
            HttpWebRequest _request = WebRequest.Create(_Html2PdfUrl) as HttpWebRequest;
            _request.Method = WebRequestMethods.Http.Post;
            _request.ContentType = "application/x-www-form-urlencoded";
            _request.ContentLength = _data.Length;
 
            Stream sw = _request.GetRequestStream();
            sw.Write(_data, 0, _data.Length);
            sw.Close();
 
            using (HttpWebResponse response = _request.GetResponse() as HttpWebResponse)
            {
                String ContentType = response.ContentType;
 
                // Get the response stream 
                StreamReader reader = new StreamReader(response.GetResponseStream(), System.Text.Encoding.ASCII);
 
                // Read the whole contents and return as a string 
                _Result = reader.ReadToEnd();
            }