信号器hubconnection.Start不工作

Question

我使用SignalR，但我遇到了问题。有一个名为Discussion.when数据插入，触发调用API服务

的表

API服务中的代码

public async void Triger(int ID)
{
    try
    {
       var hubConnection = new HubConnection("http://localhost:57278");
        IHubProxy stockTickerHubProxy = hubConnection.CreateHubProxy("DiscussionHub");
        await hubConnection.Start(new LongPollingTransport());
        stockTickerHubProxy.Invoke("RefreshData", ID);
    }
    catch (Exception ex)
    {
        int i = 0;
    }
}

但是它引发了以下错误

  

StatusCode：404，ReasonPhrase：'Not Found'，版本：1.1，内容：
  System.Net.Http.StreamContent，Headers：{

     

X-SourceFiles：   =？UTF-8 2 B 4 QzpcVXNlcnNcw7ZtZXJcRG9jdW1lbnRzXGFwY3Vyc1xhcGN1cnNcYXBjdXJzXERpc2N1c3Npb25IdWJcc2lnbmFsclxuZWdvdGlhdGU =？=   缓存控制：私人日期：2018年2月27日星期二17:40:20 GMT
  服务器：Microsoft-IIS / 10.0 X-AspNet-版本：4.0.30319
  X-Powered-By：ASP.NET Content-Length：3284 Content-Type：   为text / html;字符集= UTF-8

     

}

，这是Hub类

public class DiscussionHub : Hub
{
    public static object _lock = new object();
    public static DiscussionsModel dataList = new DiscussionsModel();

    public void RefreshData(int ID)
    {
        lock (_lock)
        {
            SubDiscussionModel sdm = new SubDiscussionModel();
            DbDataContext db = new DbDataContext();
            if (!dataList.subDiscussions.Any())
            {
                var discussion = (from q in db.Discussions
                                  select new DiscussionsModel
                                  {
                                      id = q.id,
                                      user = q.User,
                                      discussionText = q.DiscussionText,
                                      createdDate = q.CreatedDate,
                                      viewCount = q.ViewCount,
                                      shortTitle = q.ShortTitle,
                                      isWantEmail = q.IsWantEmail,
                                      status = q.Status,
                                  }).Where(a => a.id == 1).FirstOrDefault();

                DiscussionsModel data = discussion;
                dataList = data;
            }
            else
            {

                SubDiscussion data = db.SubDiscussions.SingleOrDefault(ga => ga.id == ID);
                sdm.id = data.id;
                sdm.status = data.Status;
                sdm.text = data.Text;
                sdm.user = data.User;
                sdm.createdDate = data.CreatedDate;
                sdm.discussionId = data.DiscussionId;

                dataList.subDiscussions.Add(sdm);
            }

            string viewName = @"~/Views/discussions/SubDiscussionListPartial.cshtml";
            var discussionScreen = Helper.GetRazorViewAsString(dataList, viewName);
            Clients.All.refreshData(discussionScreen);

        }
    }
}