.NET HttpClient 关于 Send 问题

              一个数据采集项目中，使用 HttpClient  携带COOKIE 对 被采集的系统调用API的方式进行数据请求，使用 HttpClient  过程中发现，通过HttpClient  中 Send方式进行数据请求时 ”JSESSIONID“缺失！

           HttpClient 初始化：

 1             #region 初始化 HttpClient
 2 
 3             var handler = new HttpClientHandler();
 4             handler.UseCookies = true;
 5             handler.AllowAutoRedirect = true;
 6             handler.CookieContainer = cookieContainer;
 7             handler.Proxy = webProxy;
 8             handler.UseProxy = true;
 9             HttpClient httpClient = new HttpClient(handler);
10             httpClient.BaseAddress = new Uri("**********");
11             httpClient.DefaultRequestHeaders.Add("Accept", "application/json, text/javascript, */*; q=0.01");
12             httpClient.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0;********");
13             httpClient.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, br");
14 
15             #endregion
16 　　

           分别以 Send 和 Post 两种请求方式请求：

 1             #region Send Request
 2 
 3             HttpRequestMessage httpRequestTreeMessage = new HttpRequestMessage();
 4             httpRequestTreeMessage.Method = HttpMethod.Post;
 5             httpRequestTreeMessage.RequestUri = new Uri(request.httpClient.BaseAddress + RequestAddress);
 6             httpRequestTreeMessage.Content = null;
 7             HttpResponseMessage  SendResponse  = request.httpClient.Send(httpRequestTreeMessage);
 8             var SendResponseData = await SendResponse.Content.ReadAsStringAsync();
 9 
10             #endregion
11 
12 
13             #region Post Request
14 
15             HttpResponseMessage PostResponse = request.httpClient.PostAsync(RequestAddress,null ).Result;
16 
17             var PostResponseData = await PostResponse.Content.ReadAsStringAsync();
18 
19             #endregion

           1.Send 方式的请求头：

HttpClient  Send

           2.Post 方式的请求头：

HttpClient  Post

           从两次请求头分析，Send 请求 Cookie 不包含 "JSESSIONID"，而在 Post 请求 Cookie 中包含  "JSESSIONID" 。