Content-Type boundary 问题

    public static ApiResult PostBatch()
        {
            object obj = new object();
            string url = "$batch";

            var batchUniqueIdHeader = "batch_AAA123";//Guid.NewGuid().ToString();

            ICredentials credentials = null; EnsureCredentials(ref credentials);
            using (var client = new CRMClient(credentials, null))
            {
                var data = new
                {
                    neo_phonesysstatus = 110000001
                };
                var multipartContent = new MultipartContent("mixed", "batch_AAA123");
                var stringContent = new StringContent(string.Format(@"
            --{0}
            Content-Type: application/http
            Content-Transfer-Encoding:binary
            Content-ID: 1

            PATCH  http://dev.crm.xiaoniu66.com/DevCRM/api/data/v8.0/neo_marketings(B1D14BC0-2B6B-E611-80C4-005056A97E8D) HTTP/1.1
            Content-Type: application/json;type=entry

            {1}

            --{0}--
            ", "changeset_BBB456", data.ToJson()));
                stringContent.Headers.Clear();
                stringContent.Headers.Add("Content-Type", "multipart/mixed;boundary=batch_AAA123");
                multipartContent.Add(stringContent);
                HttpResponseMessage response = client.PostAsync(url, multipartContent).Result;
                var result = HandleApiResult(response);
                return result;
            }
        }