Communicating with a socket.io server via c#

Question

Is there a c# client that follows the socket.io protocol? I have a socket.io server that is communicating with a socket.io javascript client via a website, but i also need to connect a c# piece to it that can send and receive messages. Is there a clean way to do this currently or will I have to write my own client.

Pagel

@jgauffin, not really, as socket.io mixes in it's own secret sauce too. – Hardwood

Seems that at least some part of socket.io.js would have to be re-written in .NET for this to work. I tried fiddling with WebSocket4Net as a starting point, but it seems that there is still a ways to go. – Lewes

Perhaps this helps? groups.google.com/group/socket_io/browse_thread/thread/… – Lewes

Incomplete implementation abandoned Feb 2011: github.com/jouz/socket.io-unity-client – Lewes

2012 attempt: socketiowebsockets.codeplex.com/releases/view/80290 – Lewes

Answer 1

There is a project on codeplex ( NuGet as well ) that is a C# client for socket.io. (I am the author of this project - so I'm biased) I couldn't find exactly what I needed in a client, so I built it and released it back into the open.

Example client style:

socket.On("news", (data) =>    {
Console.WriteLine(data);
});

Helical

I can't wait to give it a try. Thanks – Pagel

Wahooo! Thanks Jim, I'm going to give this a whirl tonight! Saturday Evening Planned I'm too cool. Is this on github? Also would this run find on client profile 4.0? – Oersted

Jim, your library simply rocks! This solved a lot of issues I was having to connect a local printer with a cloud node app. – Uniflorous

Hi Jim I couldn't find any comment in this code, could n't understand the flow, can you tell me how can I use your code to connect to pre-existing node. I have node which I am using to connect to my driver app in (Android), a taxi system. – Friedrich

I'm pretty sure this client is incompatible with a socket.io server > v1.0. – Magician

Downvote: this project has not been maintained in years. The websocket-sharp answer should be accepted. – Haplo

Answer 2

Use the following library: https://github.com/sta/websocket-sharp It is available via NuGet:

PM> Install-Package WebSocketSharp -Pre

To connect to a Socket.IO 1.0 + server, use the following syntax:

using (var ws = new WebSocket("ws://127.0.0.1:1337/socket.io/?EIO=2&transport=websocket"))
{
    ws.OnMessage += (sender, e) =>
      Console.WriteLine("New message from controller: " + e.Data);

    ws.Connect();
    Console.ReadKey(true);
}

In other words, append this to the localhost:port - "socket.io/?EIO=2&transport=websocket".

My full server code: https://gist.github.com/anonymous/574133a15f7faf39fdb5

Guillema

how would you do this if didn't know the port ahead of time? – Camisole

I don't think that would be possible. Do you have access to the computer where the socket server runs? – Guillema

I do but in production it's hosted on machine that will set the port dynamically. – Camisole

I just realized that it doesn't matter though because the site address will actually direct it to the right port on the server side – Camisole

How can connect to a room and read a particular message using this ? and how can i have retries on disconnection ? – Skyway

How can I achieve this, io.emit('chat message', message); I tried ws.send("some string") but that closes the current socket connection and message isn't received on server moreover 'chat message' how to pass this event name. – Caecum

@AniketBhansali for using things like io.emit, you need to create your own wrapper. Or best you need to pass ws.send with a JSON string and deserialize at client side to find out the message room. – Juback

Thank you! In my case - add in your code: ws.Send("42[\"chat message\",\"HELLO !\"]"); and it works ! – Reactive

Answer 3

This package supports the latest protocol.
Github - https://github.com/HavenDV/H.Socket.IO/
C# Live Example - https://dotnetfiddle.net/FWMpQ3/
VB.NET Live Example - https://dotnetfiddle.net/WzIdnG/
Nuget:

Install-Package H.Socket.IO

using System;
using System.Threading.Tasks;
using H.Socket.IO;

#nullable enable

public class ChatMessage
{
    public string? Username { get; set; }
    public string? Message { get; set; }
    public long NumUsers { get; set; }
}
    
public async Task ConnectToChatNowShTest()
{
    await using var client = new SocketIoClient();

    client.Connected += (sender, args) => Console.WriteLine($"Connected: {args.Namespace}");
    client.Disconnected += (sender, args) => Console.WriteLine($"Disconnected. Reason: {args.Reason}, Status: {args.Status:G}");
    client.EventReceived += (sender, args) => Console.WriteLine($"EventReceived: Namespace: {args.Namespace}, Value: {args.Value}, IsHandled: {args.IsHandled}");
    client.HandledEventReceived += (sender, args) => Console.WriteLine($"HandledEventReceived: Namespace: {args.Namespace}, Value: {args.Value}");
    client.UnhandledEventReceived += (sender, args) => Console.WriteLine($"UnhandledEventReceived: Namespace: {args.Namespace}, Value: {args.Value}");
    client.ErrorReceived += (sender, args) => Console.WriteLine($"ErrorReceived: Namespace: {args.Namespace}, Value: {args.Value}");
    client.ExceptionOccurred += (sender, args) => Console.WriteLine($"ExceptionOccurred: {args.Value}");
    
    client.On("login", () =>
    {
        Console.WriteLine("You are logged in.");
    });
    client.On("login", json =>
    {
        Console.WriteLine($"You are logged in. Json: \"{json}\"");
    });
    client.On<ChatMessage>("login", message =>
    {
        Console.WriteLine($"You are logged in. Total number of users: {message.NumUsers}");
    });
    client.On<ChatMessage>("user joined", message =>
    {
        Console.WriteLine($"User joined: {message.Username}. Total number of users: {message.NumUsers}");
    });
    client.On<ChatMessage>("user left", message =>
    {
        Console.WriteLine($"User left: {message.Username}. Total number of users: {message.NumUsers}");
    });
    client.On<ChatMessage>("typing", message =>
    {
        Console.WriteLine($"User typing: {message.Username}");
    });
    client.On<ChatMessage>("stop typing", message =>
    {
        Console.WriteLine($"User stop typing: {message.Username}");
    });
    client.On<ChatMessage>("new message", message =>
    {
        Console.WriteLine($"New message from user \"{message.Username}\": {message.Message}");
    });
    
    await client.ConnectAsync(new Uri("wss://socketio-chat-h9jt.herokuapp.com/"));

    await client.Emit("add user", "C# H.Socket.IO Test User");

    await Task.Delay(TimeSpan.FromMilliseconds(200));

    await client.Emit("typing");

    await Task.Delay(TimeSpan.FromMilliseconds(200));

    await client.Emit("new message", "hello");

    await Task.Delay(TimeSpan.FromMilliseconds(200));

    await client.Emit("stop typing");

    await Task.Delay(TimeSpan.FromSeconds(2));

    await client.DisconnectAsync();
}

It also supports namespaces:

// Will be sent with all messages(Unless otherwise stated).
// Also automatically connects to it.
client.DefaultNamespace = "my";

// or

// Connects to "my" namespace.
await client.ConnectAsync(new Uri(LocalCharServerUrl), cancellationToken, "my");
// Sends message to "my" namespace.
await client.Emit("message", "hello", "my", cancellationToken);

Joaniejoann

Can you show how you're connecting? I am not having much luck with connecting to Paymium api which uses a namespace and path – Anteroom

Updated my answer with a namespace usage example. – Joaniejoann

Answer 4

Well, I found another .Net library which works great with socket.io. It is the most updated too. Follow the below link,

Quobject/SocketIoClientDotNet

using Quobject.SocketIoClientDotNet.Client;

var socket = IO.Socket("http://localhost");
socket.On(Socket.EVENT_CONNECT, () =>
{
    socket.Emit("hi");
});

socket.On("hi", (data) =>
{
    Console.WriteLine(data);
    socket.Disconnect();
});
Console.ReadLine();

Hope, it helps someone.

Anstus

This library is now deprecated. – Cession

Answer 5

I tried all of the above but somehow they doesn't talk with the service I am integrating with (maybe the service is bugged, I don't know which). So I wrote my own.

https://github.com/it9gamelog/socketio-with-ws-client

A minimalistic, single-file client implementation. Since socket-io is a dying technology, and the specification is quite complicated, bugs on either side might just never get fixed at any time. A single file approach is at least easier to tune, expand and debug.

Gibeon

Answer 6

This depends on how your webserver looks. In some cases it might be applicable to make a listener for regular sockets too.
Otherwise, you will probably have to make your own client. However, you will probably only need to implement the WebSocket transport so it should be fairly straightforward anyway.

For what it's worth I'd suggest looking at the question "Is there a WebSocket client implemented for .NET?" and my (fairly simple) WebSocket Socket.IO transport client implementation for Java.

Supernational

Ideally im looking for a wrapper of the socket.io client written in c#. I can write a socket webserver, the problem is the socket.io protocol. – Pagel

@Dested, Then I would suggest taking a look at the links I provided. – Hardwood