CODEWITHSUNDEEP
asp.netsignalr
Thomas
Thomas

Reputation: 34188

Want to send message to only connected client SignalR

here i got bit code for signalr and included.

client code

$(function () {
    // Proxy created on the fly
    var chat = $.connection.chat;

    // Declare a function on the chat hub so the server can invoke it
    chat.addMessage = function (message) {
        $('#messages').append('<li>' + message + '');
    };

    $("#broadcast").click(function () {
        // Call the chat method on the server
        chat.send($('#msg').val());
    });

    // Start the connection
    $.connection.hub.start();
});

server code

public class Chat : Hub
{
    public void Send(string message)
    {
        // Call the addMessage method on all clients
        Clients.addMessage(message);
    }
}

just see this line Clients.addMessage(message); addMessage() will invoke addMessage() function in client side but think suppose when i am sending data or message to specific client and if that is client is not connected any more then what will happen?

is there any provision in signalr like can we determine that client is connected before delivering data to specific client.

i want to detect a specific client is connected or not before sending data to client. if client is not connected then i will store data in db for that specific user. please help me with sample code that how to detect a specific client is connected or not? thanks

Upvotes: 2

Views: 3168

Answers (1)

Arindam Nayak
Arindam Nayak

Reputation: 7462

I have a suggestion for this. Declare a static List , in Chat class. Use following code for OnConnect event.

public override Task OnConnected() {
    string connectionId = Context.ConnectionId;
    // Store this connectionId in list -- This will be helpful for tracking list of connected clients.
    return base.OnConnected();
}

And have OnDisconnect method.

public override Task OnDisconnected() {
        string connectionId = Context.ConnectionId;
        // Remove this connectionId from list
        // and save the message for disconnected clients.
        // Maintain list of disconnected clients in a list, say ABC
        return base.OnDisconnected();
}

On send method execute for connected clients only.

public void Send(string message){
        // Call the addMessage method on all clients
        Clients.AllExcept(ABC.ToArray()).addMessage(message);
}

You can refer to this link

Upvotes: 1

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