AJAX在C#中處理WebSocket連接斷開

在C#中，處理WebSocket連接斷開可以通過捕獲WebSocketException異常來實現。當WebSocket連接斷開時，會觸發這個異常。你可以在catch語句中處理這個異常，例如記錄日志或者重新建立連接。

下面是一個簡單的示例，展示了如何在C#中處理WebSocket連接斷開：

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

namespace WebSocketExample
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var uri = new Uri("wss://example.com/websocket");
            using (var client = new ClientWebSocket())
            {
                await client.ConnectAsync(uri, CancellationToken.None);
                Console.WriteLine("Connected to WebSocket server.");

                var buffer = new byte[1024 * 4];
                var segment = new ArraySegment<byte>(buffer);

                while (client.State == WebSocketState.Open)
                {
                    try
                    {
                        var result = await client.ReceiveAsync(segment, CancellationToken.None);
                        if (result.MessageType == WebSocketMessageType.Close)
                        {
                            await client.CloseAsync(WebSocketCloseStatus.NormalClosure, "Closed by the server", CancellationToken.None);
                            Console.WriteLine("WebSocket closed by the server.");
                            break;
                        }
                        else
                        {
                            // Process received data
                            Console.WriteLine($"Received message: {Encoding.UTF8.GetString(buffer, 0, result.Count)}");
                        }
                    }
                    catch (WebSocketException ex)
                    {
                        Console.WriteLine($"WebSocket connection closed unexpectedly: {ex.Message}");
                        break;
                    }
                }
            }
        }
    }
}

在這個示例中，我們使用ClientWebSocket類連接到WebSocket服務器。然后，我們使用while循環不斷地從服務器接收數據。如果接收到關閉消息，我們關閉WebSocket連接并退出循環。如果在接收數據時發生WebSocketException異常，我們捕獲這個異常并打印錯誤信息，然后退出循環。