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C# websocketserver怎么保持連接

c#
小樊
102
2024-07-16 15:51:47
欄目: 編程語言

要保持連接，您可以使用心跳機制來定期發(fā)送消息以確保連接保持活動狀態(tài)。以下是一個簡單的示例代碼，演示如何使用C#編寫一個WebSocket服務器并實現(xiàn)心跳功能：

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

class WebSocketServer
{
    private HttpListener listener;
    private CancellationTokenSource cancellationTokenSource;

    public async Task Start(string url)
    {
        listener = new HttpListener();
        listener.Prefixes.Add(url);
        listener.Start();

        Console.WriteLine("Server started");

        while (true)
        {
            HttpListenerContext context = await listener.GetContextAsync();
            if (context.Request.IsWebSocketRequest)
            {
                ProcessWebSocketRequest(context);
            }
            else
            {
                context.Response.StatusCode = 400;
                context.Response.Close();
            }
        }
    }

    private async Task ProcessWebSocketRequest(HttpListenerContext context)
    {
        WebSocketContext webSocketContext = await context.AcceptWebSocketAsync(null);
        WebSocket webSocket = webSocketContext.WebSocket;

        // Start a task to keep the connection alive
        cancellationTokenSource = new CancellationTokenSource();
        Task.Run(async () =>
        {
            while (webSocket.State == WebSocketState.Open)
            {
                try
                {
                    await webSocket.SendAsync(new ArraySegment<byte>(Encoding.UTF8.GetBytes("Ping")), WebSocketMessageType.Text, true, cancellationTokenSource.Token);
                    await Task.Delay(5000); // Send ping every 5 seconds
                }
                catch (WebSocketException)
                {
                    break;
                }
            }
        });

        // Handle incoming messages
        byte[] buffer = new byte[1024];
        while (webSocket.State == WebSocketState.Open)
        {
            WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), cancellationTokenSource.Token);
            if (result.MessageType == WebSocketMessageType.Close)
            {
                break;
            }
            else if (result.MessageType == WebSocketMessageType.Text)
            {
                string message = Encoding.UTF8.GetString(buffer, 0, result.Count);
                Console.WriteLine("Received message: " + message);
            }
        }

        await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "", CancellationToken.None);
    }

    public void Stop()
    {
        cancellationTokenSource?.Cancel();
        listener.Stop();
        listener.Close();
    }
}

class Program
{
    static async Task Main(string[] args)
    {
        WebSocketServer server = new WebSocketServer();
        await server.Start("http://localhost:8080/");
    }
}

在上面的示例中，我們創(chuàng)建了一個簡單的WebSocket服務器，并在每5秒發(fā)送一個"Ping"消息以保持連接活動狀態(tài)。您可以根據(jù)需求調整心跳間隔和消息內(nèi)容。在客戶端斷開連接時，服務器會停止心跳并關閉連接。

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