HttpClient setting boundary with content-type

Question

I am using javascript to communicate with a third party service. As part of their authentication process they need the \"multipart/form\" body of the post message including

Answer 1

with HttpClient

 request.Content.Headers.Add("ContentType", "multipart/form-data, boundary=------------ThIs_Is_tHe_bouNdaRY_");

you can use HttpWebRequest

 myHttpWebRequest.Date = DateTime.Now;
 myHttpWebRequest.ContentType = "multipart/form-data, boundary=------------ThIs_Is_tHe_bouNdaRY_";