Compatibility Issues With SignalR and NetCore 3.1

Question

User1596943402 posted

I am following this tutorial to create a real-time progress bar.  This article I am following is 4 years old, and I am using a different version of Net Core.  I am using the current version, which is ASP Net Core 3.1. 

I believe the errors I am getting stem from the fact that I am using version 3.1 of Net Core.  This is the article I which I am using:

https://www.codeproject.com/Articles/1124691/SignalR-Progress-Bar-Simple-Example-Sending-Live-D

Everything seems to be running fine until I reach this part.

        public static void SendProgress(string progressMessage, double progressCount)
        {
            //IN ORDER TO INVOKE SIGNALR FUNCTIONALITY DIRECTLY FROM SERVER SIDE WE MUST USE THIS
            var hubContext = GlobalHost.ConnectionManager.GetHubContext<ProgressHub>();

            //CALCULATING PERCENTAGE BASED ON THE PARAMETERS SENT
            // var percentage = (progressCount * 100) / totalItems;
            var percentage = (progressCount);

            //PUSHING DATA TO ALL CLIENTS
            hubContext.Clients.All.AddProgress(progressMessage, percentage + "%");
        }

    }
}

The first issue is that I am getting "GlobalHost does not exist in the current context for this line of code":

var hubContext = GlobalHost.ConnectionManager.GetHubContext<ProgressHub>();

The second issue is that that I am getting "

<div>Severity Code Description Project File Line Suppression State</div> <div>Error CS0119 'HubClientsExtensions.Clients<T>(IHubClients<T>, string)' is a method, which is not valid in the given context" for this line of code:

 hubContext.Clients.All.AddProgress(progressMessage, percentage + "%");

Any suggestions would be kindly appreciated.

Answer 1

User475983607 posted

Perhaps try a more update-to-date example that uses Core rather than ASP.NET and OWIN.  I did a Google search and this was the first item in the list.

https://docs.microsoft.com/en-us/archive/msdn-magazine/2018/april/cutting-edge-discovering-asp-net-core-signalr

Answer 2

User-782232518 posted

ASP.NET SignalR is different from ASP.NET Core SignalR,

https://docs.microsoft.com/en-us/aspnet/core/signalr/version-differences?view=aspnetcore-3.1

You'd better stick to that article on ASP.NET 4.x to study the concepts first, and then learn how to migrate to ASP.NET Core. Alternatively, jump directly to ASP.NET Core.