问由于401，SignalR连接返回到长轮询。

EN

export class NotificationSignalrService {

  private connection: signalR.HubConnection;
  connectionClosedRefreshTokenSubscription: Subscription | undefined;
  startConnectionRefreshTokenSubscription: Subscription | undefined;

  constructor(@Inject(APP_CONFIG) private appConfig: any, private store: Store) {
    this.connection = new signalR.HubConnectionBuilder()
      .withUrl(`${this.appConfig.SIGNALR}/hubs/notificationhub`, this.hubConnectionOptions)
      .configureLogging(signalR.LogLevel.Debug)
      //.withAutomaticReconnect()
      .build();

    this.connection.onclose(error => {
      console.log(`Forbindelse lukket pga: ${error}`);
      this.store.dispatch(AuthActions.renewNoLoading());
      this.connectionClosedRefreshTokenSubscription = this.store.select(AuthSelectors.selectTokenRefreshed).subscribe({
        next: tokenRefreshed => {
          if (tokenRefreshed) {
            this.connectionClosedRefreshTokenSubscription?.unsubscribe();

            this.startSignalRConnection();
          }
        }
      })
    });


    this.startSignalRConnection();
    this.startListening();
  }

  startSignalRConnection() {
    this.connection.start().catch(error => {
      console.log(`Der skete en fejl ved start af signalR ${error}`);
      this.startConnectionRefreshTokenSubscription = this.store.select(AuthSelectors.selectTokenRefreshed).subscribe({
        next: tokenRefreshed => {
          if (tokenRefreshed) {
            this.startConnectionRefreshTokenSubscription?.unsubscribe();
            this.connection.start().catch(error => console.log(`Kunne ikke starte forbindelsen efter renew ${error}`));
          }
        }
      })
    });

  }

  @HostListener('window:beforeunload', ['$event'])
  beforeunloadHandler() {
    this.connection.stop();
  }

  protected get hubConnectionOptions(): IHttpConnectionOptions {
    // NOTE: The auth token must be updated for each request. So using headers option is not true.
    //       Also for websockets and some other protocols signalr cannot set auth headers.
    //       See https://docs.microsoft.com/en-us/aspnet/core/signalr/authn-and-authz?view=aspnetcore-5.0#bearer-token-authentication

    return {
      /*headers,*/
      accessTokenFactory: () => {
        return this.store.select(AuthSelectors.getLoggedInToken)
          .pipe(take(1), filter(x => x !== null), map(x => x === null ? "" : x)).toPromise();

        // this.authService.refreshLogin()
        //   .pipe(map(_ => this.authService.accessToken)).toPromise();
      }
    };

    // NOTE:
    // The access token function you provide is called before every HTTP request made by SignalR. If you need to renew the token in order to keep the connection active (because it may expire during the connection), do so from within this function and return the updated token.
    // In standard web APIs, bearer tokens are sent in an HTTP header. However, SignalR is unable to set these headers in browsers when using some transports. When using WebSockets and Server - Sent Events, the token is transmitted as a query string parameter.
  }
  getAuthToken() {
    let token = '';
    this.store.select(AuthSelectors.getLoggedInToken).pipe(take(1))
      .subscribe(authToken => token = authToken ?? "");
    return {
      Authorization: `Bearer ${token}`
    };
  }

  startListening() {
    this.connection.on("NewNotificationForUser", (notification: NotificationsEntity) =>
      this.store.dispatch(NotificationsState.NotificationsActions.newNotification({ notification }))
    );
  }

app.UseEndpoints(endpoints =>
{
    endpoints.MapControllers();
    endpoints.MapHub<NotificationHub>("/hubs/notificationhub");
});