检查使用 SignalR 的 Self Hosting 是否正在监听

Question

I am creating a console application that maintains an active Client/Server connection. To start the server I run:

string url = "http://localhost:6118";  
using (WebApp.Start<Startup>(url))  
{  
     Console.WriteLine("The Server URL is: {0}", url);  
     Console.ReadLine();  
 }

My question is how to constantly check if the Server is receiving messages. I did not find any status properties indicating that everything is working correctly.

Answer 1

To check from a separate console application (client) - There are several lifetime events you can use to check your current state such as StateChanged or ConnectionSlow.

hubConnection.ConnectionSlow += () => Console.WriteLine("Connection problems.");

Check the documentation for more information on the C# .NET Client - https://docs.microsoft.com/en-us/aspnet/signalr/overview/guide-to-the-api/hubs-api-guide-net-client#how-to-handle-connection-lifetime-events

You could do something similar in a JavaScript client as well.

In the self host console application you could create a method for a client to invoke and have the hub respond back to your client to verify it is listening. I do something similar from a "admin" page where once every few minutes through a setTimeout (Javascript) an invoke to the server is made. The response updates my page and lets me know it is running.