var path = Server.MapPath("~/themes/vehiclexml/fude/CCarInfoQuery.xml");
                using (StreamReader sr = new StreamReader(path, Encoding.Default))
                {
                    var xml = sr.ReadToEnd();
                    var client = new HttpClient();
                    var content = new StringContent(xml, Encoding.Default, "text/xml");
                    //content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("text/xml");
                    var result = client.PostAsync(apiUrl, content).Result;
                    result.Content.Headers.ContentType.CharSet = Encoding.Default.BodyName; //如果不指定返回的编码，会报"GBK"不是指定的编码
                    var str = result.Content.ReadAsStringAsync().Result;
                    ViewBag.Result = str;
                }