不处理Azure ASP.NET REST Web服务调用

Question

我正在试验新的Azure机器学习服务，并已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工具对其进行POST时，可以获得预期的结果。

我的问题是让我的ASP.NET代码可以使用它。 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。 我知道它可以正确地发布所有内容，并且在我跟踪通信时，Web服务返回正确的JSON。 但是由于某种原因，我的代码无法确认此返回。

我已经从Azure网站和Visual Studio中的本地站点运行了此代码

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

此问题是由于这里讨论的错误所致- 使用await / async时HttpClient.GetAsync（...）从不返回

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);