HttpClient'Net返回404(Not found:无法找到控制器)

我必须进行身份验证，然后在asp.net中请求Web Api。验证已正确完成。但是，当我将会话值传递给新请求以生成某个响应时，响应返回Controller not found错误。我试图实现它在Asp。. Net MVC应用程序。

下面是主索引的代码:

public async Task<ActionResult> Index()
    {
        var result = "";
        string json = " { '"username'": '"webservice'", '"password'": '"iIU2piH6wpBF92T'" }";
        var request = (HttpWebRequest)WebRequest.Create("https://os.mcparcel.com/osapi/user/login.json");
        request.Method = "POST";
        request.UserAgent = "MCParcel Plugin";
        request.ContentType = "application/json";
        using (var s = request.GetRequestStream())
        {
            using (var stw = new StreamWriter(s))
            {
                stw.Write(json);
            }
        }
        try
        {
            var response = (HttpWebResponse)request.GetResponse();
            var data = new StreamReader(response.GetResponseStream());
            result = data.ReadToEnd();//<-this gives the value for session id and name
            string key = "WucHEwRuy7trUDE7u3agEqEWrUkajuCr";
            string order_id = "MCParcel3";
            int labels_number = 1;

            var r = await Test(key, order_id, labels_number, result);
        }
        catch (WebException ex)
        {
            var errorData = new StreamReader(ex.Response.GetResponseStream());
            var errorString = errorData.ReadToEnd();
        }
        return View();
    }

下面是同一控制器内的其他函数，错误在:

<

var响应/strong>

 public static async Task<string> Test(string key, string order_id, int labels_number, dynamic results, int? shipment_id = 0)
    {
        var r = await GetShippingOptionRequest(key, order_id, labels_number, results);
        Console.WriteLine(r);
        return r;
    }

  public static async Task<string> GetShippingOptionRequest(string key, string order_id, int labels_number, dynamic results, int? shipment_id = 0)
    {
        string json = " { '"key'": '"" + key + "'", '"order_id'": '"" + order_id + "'", '"labels_no'": " + labels_number + ", '"shipment_id'": " + shipment_id + "";

        var dynObj = JsonConvert.DeserializeObject<LoginResponse>(results);
        using (var client = new HttpClient())
        {
            client.DefaultRequestHeaders.Add("Method", "POST");
            client.DefaultRequestHeaders.Add("ContentType", "application/json");
            client.DefaultRequestHeaders.Add("UserAgent", "MCParcel Plugin");
            client.DefaultRequestHeaders.Add("sessid", dynObj.sessid);
            client.DefaultRequestHeaders.Add("session_name", dynObj.session_name);
            client.DefaultRequestHeaders.Add("key", key);
            client.DefaultRequestHeaders.Add("order_id", order_id);
            client.DefaultRequestHeaders.Add("labels_number", Convert.ToString(labels_number));
            client.DefaultRequestHeaders.Add("shipment_id", Convert.ToString(shipment_id));

            //the code below is the required response that is not returning values and returning 404 error
            var response = await client.GetStringAsync("https://os.mcparcel.com/osapi/service_os_api/get_label_info.json");
            return response;
        }
    }

响应应该返回类似以下内容:

{"source_labels":("https://os.mcparcel.com/sites/os.mcparcel.com/files/sourcepdflabels/labels_8c1e3033a8d23c632006639f39ef6964.pdf"),"跟踪":"https://os.mcparcel.com/track_and_trace/(J) JD0000900581338100135004","labels_file":"https://os.mcparcel.com/sites/os.mcparcel.com/files/pdf_labels/70994c37ad2a99d4047e0684c3e05c1f.pdf"}

任何帮助都将非常感激。提前感谢!!