1 public void SaveSequenceDiagram(string data, string outFile, SequenceStyle style, SequenceOutputFormat outputFormat)
 2 {
 3     var request = WebRequest.Create("http://www.websequencediagrams.com");
 4     request.Method = "POST";
 5 
 6     string postData = string.Format("style={0}&format={1}&message={2}", style, outputFormat, HttpUtility.UrlEncode(data, Encoding.UTF8));
 7 
 8     byte[] byteArray = Encoding.UTF8.GetBytes(postData);
 9     request.ContentType = "application/x-www-form-urlencoded";
10     request.ContentLength = byteArray.Length;
11 
12     //because error: The remote server returned an error: (417) Expectation Failed.
13     System.Net.ServicePointManager.Expect100Continue = false;
14 
15     Stream dataStream = request.GetRequestStream();
16     dataStream.Write(byteArray, 0, byteArray.Length);
17     dataStream.Close();
18 
19     dataStream = request.GetResponse().GetResponseStream();
20     if (dataStream == null) return;
21 
22     using (var reader = new StreamReader(dataStream))
23     {
24         string responseFromServer = reader.ReadToEnd();
25         var image = responseFromServer.Substring(12, 9);
26 
27         using (var webClient = new WebClient())
28         {
29             byte[] resp = webClient.DownloadData(string.Format("http://www.websequencediagrams.com?{0}={1}", outputFormat, image));
30             using (var fileStream = new FileStream(outFile, FileMode.OpenOrCreate))
31             {
32                 fileStream.Write(resp, 0, resp.Length);
33             }
34         }
35     }
36 
37     dataStream.Close();
38 }

1 public enum SequenceOutputFormat
2 {
3     img,
4     pdf,
5     png,
6     svg
7 }

 1 public enum SequenceStyle
 2 {
 3     @default,
 4     earth,
 5     modernblue,
 6     mscgen,
 7     omegapple,
 8     qsd,
 9     rose,
10     roundgreen,
11     napkin,
12 }

1 SaveSequenceDiagram("Alice->Bob: Authentication Request\nactivate Bob\nBob->Alice: Authentication Response\ndeactivate Bob", "out.svg",
2                 SequenceStyle.roundgreen, SequenceOutputFormat.svg);