Socket io .NET (How It Works For Developers)

Socket.IO, a JavaScript library, empowers web clients and servers to engage in real-time communication. It consists of two parts:

Parts of Socket IO

• Client-side library: Runs in the browser.
• Server-side library: Runs on Node.js.

Install the Necessary Packages

To use Socket.IO for .NET applications in Visual Studio, you'll need a compatible server implementation. One such implementation is the SocketIoClientDotNet for .NET, which allows a Socket.IO client to connect to a Socket.IO from a C# application.

First, install the required NuGet packages. You can do this via the Package Manager Console or by adding the references to your project file:

Install-Package SocketIoClientDotNet

Screenshot of the SocketIoClientDotNet package

Executing this command will incorporate the Socket.IO client library into your .NET project, empowering your C# application to connect with a Socket.IO server, facilitating communication between users and the system.

Before diving into the C# client, let’s set up a basic example of Socket IO using .NET Core Console App in Visual Studio. This will help us test the client implementation.

Creating Server Implementations

The following code sets up a basic Socket.IO server in C# that listens for client connections on port 3000. When a client sends a message, the server logs the message and responds back to the client, confirming receipt.

using System;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Quobject.SocketIoClientDotNet.Client;

namespace DemoApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // Connect to the Socket.IO server
            var socket = IO.Socket("http://localhost:3000");

            // Listen for the "connect" event
            socket.On(Socket.EVENT_CONNECT, () =>
            {
                Console.WriteLine("Connected to the server!");

                // Emit a message to the server
                socket.Emit("message", "Hello from C# client!");

                // Listen for messages from the server
                socket.On("message", (data) =>
                {
                    Console.WriteLine("Message from server: " + data);
                });
            });

            // Listen for the "disconnect" event
            socket.On(Socket.EVENT_DISCONNECT, () =>
            {
                Console.WriteLine("Disconnected from the server!");
            });

            // Keep the console window open
            Console.ReadLine();
        }
    }
}

using System;
using System.Net.WebSockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Quobject.SocketIoClientDotNet.Client;

namespace DemoApp
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // Connect to the Socket.IO server
            var socket = IO.Socket("http://localhost:3000");

            // Listen for the "connect" event
            socket.On(Socket.EVENT_CONNECT, () =>
            {
                Console.WriteLine("Connected to the server!");

                // Emit a message to the server
                socket.Emit("message", "Hello from C# client!");

                // Listen for messages from the server
                socket.On("message", (data) =>
                {
                    Console.WriteLine("Message from server: " + data);
                });
            });

            // Listen for the "disconnect" event
            socket.On(Socket.EVENT_DISCONNECT, () =>
            {
                Console.WriteLine("Disconnected from the server!");
            });

            // Keep the console window open
            Console.ReadLine();
        }
    }
}

Code Explanation

In the snippet, we first create a Socket.IO client instance by calling IO.Socket("http://localhost:3000"), which connects to the local server running on port 3000 on the client machine.

Upon successful connection (Socket.EVENT_CONNECT), we print a message indicating that we are connected to the server.

Then, we emit a message from the client to the server using socket.Emit("message", "Hello from C# client!"). This sends a message with the content "Hello from C# client!" to the server.

Next, we listen for messages from the server by registering a callback for the "message" event using socket.On("message", (data) => { ... }). When the server sends a "message" event, the callback function is invoked, and we print the received message to the console.

If the connection to the server is disconnected from the client (Socket.EVENT_DISCONNECT), we print a message indicating disconnection.

Finally, the Console.ReadLine() method keeps the console window open so that the program doesn't exit immediately after execution. This allows us to see the output and ensures that the program doesn't terminate prematurely.

Screenshot of the code

Install IronPDF in Visual Studio or from the command line using the NuGet Package Manager. In Visual Studio, go to the console:

• Tools -> NuGet Package Manager -> Package Manager Console

Install-Package IronPdf

IronPDF code example

Here's a simple example using IronPDF to convert binary data into a PDF File. Call the GeneratePDF method in the Main method and pass the data as a parameter that we had in the above example:

using System;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;

namespace SocketIO.Demo
{
    class Program
    {
        static async Task Main(string[] args)
        {
            // The WebSocket URI
            string uri = "wss://echo.websocket.org";

            // Creating a new WebSocket connection
            using (ClientWebSocket webSocket = new ClientWebSocket())
            {
                await webSocket.ConnectAsync(new Uri(uri), CancellationToken.None);
                Console.WriteLine("Connected to the server");

                // Sending data over the WebSocket
                byte[] sendBuffer = new byte[] { 1, 2, 3, 4 };
                await webSocket.SendAsync(new ArraySegment<byte>(sendBuffer), WebSocketMessageType.Binary, true, CancellationToken.None);
                Console.WriteLine("Data sent to the server");

                // Receiving data from the WebSocket
                byte[] receiveBuffer = new byte[1024];
                WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(receiveBuffer), CancellationToken.None);
                byte[] data = new byte[result.Count];
                Array.Copy(receiveBuffer, data, result.Count);
                Console.WriteLine("Received data: " + BitConverter.ToString(data));

                // Data to generate in PDF file
                string pdfData = BitConverter.ToString(data);
                PDFGenerator.GeneratePDF(pdfData);
            }
        }
    }
}

using System;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;

namespace SocketIO.Demo
{
    class Program
    {
        static async Task Main(string[] args)
        {
            // The WebSocket URI
            string uri = "wss://echo.websocket.org";

            // Creating a new WebSocket connection
            using (ClientWebSocket webSocket = new ClientWebSocket())
            {
                await webSocket.ConnectAsync(new Uri(uri), CancellationToken.None);
                Console.WriteLine("Connected to the server");

                // Sending data over the WebSocket
                byte[] sendBuffer = new byte[] { 1, 2, 3, 4 };
                await webSocket.SendAsync(new ArraySegment<byte>(sendBuffer), WebSocketMessageType.Binary, true, CancellationToken.None);
                Console.WriteLine("Data sent to the server");

                // Receiving data from the WebSocket
                byte[] receiveBuffer = new byte[1024];
                WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(receiveBuffer), CancellationToken.None);
                byte[] data = new byte[result.Count];
                Array.Copy(receiveBuffer, data, result.Count);
                Console.WriteLine("Received data: " + BitConverter.ToString(data));

                // Data to generate in PDF file
                string pdfData = BitConverter.ToString(data);
                PDFGenerator.GeneratePDF(pdfData);
            }
        }
    }
}

PDF Generation Class code

using IronPdf;

namespace SocketIO.Demo
{
    public class PDFGenerator
    {
        public static void GeneratePDF(string data)
        {
            IronPdf.License.LicenseKey = "Your-Licence-Key-Here";
            Console.WriteLine("PDF Generating Started...");

            // Instantiate Renderer
            var renderer = new ChromePdfRenderer();
            Console.WriteLine("PDF Processing ....");

            var pdf = renderer.RenderHtmlAsPdf($"<h1>Received Data</h1><p>{data}</p>");
            string filePath = "Data.pdf";
            pdf.SaveAs(filePath);
            Console.WriteLine($"PDF Generation Completed. File Saved as {filePath}");
        }
    }
}

using IronPdf;

namespace SocketIO.Demo
{
    public class PDFGenerator
    {
        public static void GeneratePDF(string data)
        {
            IronPdf.License.LicenseKey = "Your-Licence-Key-Here";
            Console.WriteLine("PDF Generating Started...");

            // Instantiate Renderer
            var renderer = new ChromePdfRenderer();
            Console.WriteLine("PDF Processing ....");

            var pdf = renderer.RenderHtmlAsPdf($"<h1>Received Data</h1><p>{data}</p>");
            string filePath = "Data.pdf";
            pdf.SaveAs(filePath);
            Console.WriteLine($"PDF Generation Completed. File Saved as {filePath}");
        }
    }
}