I am having a Visual Studio 2019 based SignalR Application, where client connects to server.

Following javascript function is called when a page is loaded and it connects to a running server with a successful connectionid.

function Connect() {

        $.connection.hub.url = url;

        stockTickerHubProxy = $.connection.mobileStockTickerHub;
        if (stockTickerHubProxy) {
            $.connection.hub.start().done(function () {
                console.log("Connected...");
                connectionId = $.connection.hub.id;
                console.log(connectionId)
                stockTickerHubProxy.server.setUserName(code);
            })
                .fail(function () {
                    alert("Can't connect");
                })
                ;

            stockTickerHubProxy.client.addMessage = function (name, message) {
                console.log(name   ":"   message);
            }
            stockTickerHubProxy.client.showtradenotification = function (msg) {
                alert(msg)
            }
            
            $.connection.hub.disconnected(function () {
                console.log("Server disconnected.");
            });
            $.connection.hub.reconnecting(function () {
                console.log("Server reconnecting...");
            });
            $.connection.hub.reconnected(function () {
                console.log("Server reconnected...");
                Connect();
            });
            $.connection.hub.error(function (error) {
                console.log('SignalR error: '   error)
            });
        }

    }

On server, I am executing following test code for checking the function running in javascript html page. Following is the code.

private async void button1_ClickAsync(object sender, EventArgs e)
    {
        mhubContext = GlobalHost.ConnectionManager.GetHubContext<MobileStockTickerHub>();
        await mhubContext.Clients.All.showtradenotification("Hello");
    }

Following is the hub class MobileStockTickerHub

public class MobileStockTickerHub : Hub
{
    
    //Called when a client is connected
    public override Task OnConnected()
    {
        _users.TryAdd(Context.ConnectionId, Context.ConnectionId);
        return base.OnConnected();
    }
    public override Task OnDisconnected(bool stopCalled)
    {
        string username;
        _users.TryRemove(Context.ConnectionId, out username);
        return base.OnDisconnected(stopCalled);
    }
    public override Task OnReconnected()
    {
        _users.TryAdd(Context.ConnectionId, Context.ConnectionId);
        return base.OnReconnected();
    }
    public string SetUserName(string userName)
    {
        _users[Context.ConnectionId] = userName;
        return "Received ping from "   userName;
    }
    
    
}

Again, when button1_ClickAsync is fired, there is no activity on the webpage, that should fire showtradenotification with an alert message.

Let me know where I am wrong. Thanks.

CodePudding user response：

Move your client function before your hub.start. You should always register at least one function before your start. See the note regarding in the docs.