带有Mltipart / Form-data连接的HttpRequestMessage意外关闭

Question

我正在尝试将一些XML发布到Web服务器。为此，我必须使用HTTP协议，Post方法，multipart / form-data Content-Type，带有1个参数，名为＆＃34; xmlinfo＆＃34;包含我上传的XML。服务器使用基本身份验证。

我不断收到以下错误消息：

  

System.Net.Http.HttpRequestException：发送请求时发生错误---＆gt; System.Net.WebException：底层连接已关闭：连接意外关闭。

我不确定为什么会发生这种情况，因为我会在没有问题的情况下向其他服务器发帖;但是，这些帖子不涉及多部分/表单数据内容类型。我正在寻找有关如何绕过它的建议。

以下是我目前在将xml发布到服务器时遇到问题的功能：

    public static async Task<Object> SaveXMLAsync(string xml)
    {
        Object strResult = String.Empty;

        using (HttpClientHandler handler = new HttpClientHandler())
        {
            NetworkCredential credentials = new NetworkCredential();
            credentials.UserName = user;
            credentials.Password = password;
            handler.Credentials = credentials;

            using (var webClient = new HttpClient(handler))
            {
                webClient.BaseAddress = new Uri(ip);
                webClient.DefaultRequestHeaders.Accept.Clear();

                using (HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, String.Format("{0}import/xml", ip)))
                {

                    using (var content = new MultipartFormDataContent("----MyBoundary"))
                    {
                        StringContent xmlContent = new StringContent(xml, Encoding.UTF8, "application/xml");
                        content.Add(xmlContent, "xmlinfo");
                        request.Content = content;
                        request.Headers.ExpectContinue = false;
                        try
                        {
                            var response = await webClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, CancellationToken.None);
                            if (response.IsSuccessStatusCode)
                            {
                                var result = response.Content.ReadAsStringAsync();
                                strResult = result.Result;
                            }
                            else
                            {
                                strResult = string.Format("Problem: {0}", response.RequestMessage);
                            }
                        }
                        catch (Exception ex)
                        {
                            strResult = ex.ToString();
                        }
                    }
                }
            }
        }

        return strResult;
    }