c# - 不处理 Azure ASP.NET REST Web 服务调用

Question

我正在尝试新的 Azure 机器学习服务，并根据我的模型创建了一个 Web 服务。该服务运行良好，因为当我使用 HTTPS 工具进行 POST 时，我得到了预期的结果。

我的问题是让我的 ASP.NET 代码能够使用它。我正在使用通过机器学习 Web 服务详细信息页面提供的代码。我知道它正确地发布了所有内容，并且当我对通信进行数据包跟踪时，Web 服务会返回正确的 JSON。但由于某种原因，我的代码不承认此返回。

我已从 Azure 网站和 Visual Studio 中的本地站点运行此代码

namespace website
{
    public partial class ML : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            InvokeRequestResponseService().Wait();
            //await InvokeRequestResponseService();
        }
        static async Task InvokeRequestResponseService()
        {
            using (var client = new HttpClient())
            {
                ScoreData scoreData = new ScoreData()
                {
                    FeatureVector = new Dictionary<string, string>() 
                    {
                        { "age", "0" },
                        { "education", "0" },
                        { "education-num", "0" },
                        { "marital-status", "0" },
                        { "relationship", "0" },
                        { "race", "0" },
                        { "sex", "0" },
                        { "capital-gain", "0" },
                        { "capital-loss", "0" },
                        { "hours-per-week", "0" },
                        { "native-country", "0" },
                    },
                    GlobalParameters =
                        new Dictionary<string, string>()
                        {
                        }
                };

                ScoreRequest scoreRequest = new ScoreRequest()
                {
                    Id = "score00001",
                    Instance = scoreData
                };

                const string apiKey = "dg/pwCd7zMPc57lfOSJqxP8nbtKGV7//XXXXXXXXXXXXXXXXXXXXXXXXXXXXgvdVl/7VWjqe/ixOA=="; // Replace this with the API key for the web service
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);

                client.BaseAddress = new Uri("https://ussouthcentral.services.XXXXXXX.net/workspaces/a932e11XXXXXXXXXXX29a69170eae9ed4/services/e8796c4382fb4XXXXXXXXXXXddac357/score");  

// GETS STUCK ON THE NEXT LINE
                HttpResponseMessage response = await client.PostAsJsonAsync("", scoreRequest); <---- NEVER RETURNS FROM THIS CALL

                if (response.IsSuccessStatusCode)
                {
                    string result = await response.Content.ReadAsStringAsync();
                    Console.WriteLine("Result: {0}", result);
                }
                else
                {
                    Console.WriteLine("Failed with status code: {0}", response.StatusCode);
                }
            }
        }
    }

    public class ScoreData
    {
        public Dictionary<string, string> FeatureVector { get; set; }
        public Dictionary<string, string> GlobalParameters { get; set; }
    }

    public class ScoreRequest
    {
        public string Id { get; set; }
        public ScoreData Instance { get; set; }
    }
}

Answer 1

此问题是由于此处讨论的错误造成的 - HttpClient.GetAsync(...) never returns when using await/async

基本上，您需要添加ConfigureAwait(false)方法。

所以代码行现在看起来像

HttpResponseMessage response = await client.PostAsJsonAsync("", scoreRequest).ConfigureAwait(false);