C# HttpResponseMessagePostAsync不'；t反应

我使用client.PostAsync没有收到任何响应。 我创建了xamarin表单中的按钮。它应该向服务器发送一些句子（json）并返回关于它们的信息（同样是json）。 按钮代码：

private async void button_Analyze_Clicked(object sender, EventArgs e)
    {
        Request req = new Request()
        {
            UserId = this.UserId,

            Language = Convert.ToString(picker_Language.SelectedItem) + ".",

            Text = Convert.ToString(editor1.Text)
        };
        string jsonStr = JsonConvert.SerializeObject(req);

        Dictionary<string, string> dict = new Dictionary<string, string>();
        dict.Add("s", jsonStr);

        FormUrlEncodedContent form = new FormUrlEncodedContent(dict);

        HttpResponseMessage response = await client.PostAsync(markTextUrl, form).ConfigureAwait(false);
        string result = await response.Content.ReadAsStringAsync();
        Answer answ = JsonConvert.DeserializeObject<Answer>(result);
        answersList.Add(answ);

        await DisplayAlert("", " ", "Ok");
    }

---

永远不要返回响应，它不会到达控制器功能。如果我等待此代码完成，我将获取System.OperationCanceledExeption:“操作已取消”

是否确定

MarkTexture

指向控制器代码运行的正确locahost URL和端口？是私有只读字符串MarkTexture=“”；尝试在MarkTexture前面加上前缀http://http:// 没有很好的帮助您

markTexture

没有端口，看起来您只是超时了

public string MarkText(string s) //работа с запросом из приложения
        {
            Request req = JsonConvert.DeserializeObject<Request>(s);


            if (req != null)
            {
                Models.Request request = new Models.Request()
                {
                    Text = req.Text,
                    Lang = req.Language,
                    UserId = int.Parse(req.UserId)
                };
                AnalyzeRequest(request);   

                Answer answ = new Answer()
                {
                    Language = req.Language,
                    Text = req.Text,
                    Sentences = db.Histories.Last().Text,
                    Labels = db.Histories.Last().Label   
                };

                return JsonConvert.SerializeObject(answ);
            }
            return null;
        }

HttpResponseMessage response = await client.PostAsync(markTextUrl, form).ConfigureAwait(false);