在ASP.NET Core中，如果在WebSocket握手期间发生核心错误，可以尝试以下解决方法：

1. 确保在Startup.cs文件中正确配置WebSocket中间件。在ConfigureServices方法中添加以下代码：

   services.AddWebSocketManager();
   

2. 在Configure方法中添加以下代码，以启用WebSocket中间件：

   app.UseWebSockets();
   app.MapWebSocketManager("/ws", serviceProvider.GetService());
   

3. 创建一个名为WebSocketManager的文件夹，并在其中创建一个名为WebSocketExtensions.cs的文件。在该文件中添加以下代码：

   public static class WebSocketExtensions
   {
       public static IApplicationBuilder MapWebSocketManager(this IApplicationBuilder app,
           PathString path, WebSocketHandler handler)
       {
           return app.Map(path, (appBuilder) =>
           {
               appBuilder.UseMiddleware(handler);
           });
       }
   }
   

4. 创建一个名为WebSocketManagerMiddleware.cs的文件，并添加以下代码：

   public class WebSocketManagerMiddleware
   {
       private readonly RequestDelegate _next;
       private readonly WebSocketHandler _webSocketHandler;
   
       public WebSocketManagerMiddleware(RequestDelegate next,
           WebSocketHandler webSocketHandler)
       {
           _next = next;
           _webSocketHandler = webSocketHandler;
       }
   
       public async Task InvokeAsync(HttpContext context)
       {
           if (!context.WebSockets.IsWebSocketRequest)
           {
               await _next(context);
               return;
           }
   
           var socket = await context.WebSockets.AcceptWebSocketAsync();
           await _webSocketHandler.OnConnected(socket);
   
           await Receive(socket, async (result, buffer) =>
           {
               if (result.MessageType == WebSocketMessageType.Text)
               {
                   await _webSocketHandler.ReceiveAsync(socket, result, buffer);
                   return;
               }
   
               else if (result.MessageType == WebSocketMessageType.Close)
               {
                   await _webSocketHandler.OnDisconnected(socket);
                   return;
               }
           });
   
           await _next(context);
       }
   
       private async Task Receive(WebSocket socket, Action handleMessage)
       {
           var buffer = new byte[1024 * 4];
   
           while (socket.State == WebSocketState.Open)
           {
               var result = await socket.ReceiveAsync(buffer: new ArraySegment(buffer),
                   cancellationToken: CancellationToken.None);
   
               handleMessage(result, buffer);
           }
       }
   }
   

5. 创建一个名为MyWebSocketHandler.cs的文件，并添加以下代码：

   public class MyWebSocketHandler : WebSocketHandler
   {
       private readonly WebSocketConnectionManager _connectionManager;
   
       public MyWebSocketHandler(WebSocketConnectionManager connectionManager)
       {
           _connectionManager = connectionManager;
       }
   
       public override async Task OnConnected(WebSocket socket)
       {
           await _connectionManager.AddSocket(socket);
       }
   
       public override async Task OnDisconnected(WebSocket socket)
       {
           await _connectionManager.RemoveSocket(_connectionManager.GetId(socket));
       }
   
       public override async Task ReceiveAsync(WebSocket socket, WebSocketReceiveResult result, byte[] buffer)
       {
           var message = Encoding.UTF8.GetString(buffer, 0, result.Count);
           await SendMessageToAllAsync(message);
       }
   
       private async Task SendMessageToAllAsync(string message)
       {
           foreach (var pair in _connectionManager.GetAll())
           {
               if (pair.Value.State == WebSocketState.Open)
               {
                   await SendMessageAsync(pair.Value, message);
               }
           }
       }
   
       private async Task SendMessageAsync(WebSocket socket, string message)
       {
           var buffer = Encoding.UTF8.GetBytes(message);
           await socket.SendAsync(buffer, WebSocketMessageType.Text, true, CancellationToken.None);
       }
   }
   

通过按照上述步骤配置WebSocket中间件并创建处理程序，可以解决ASP.NET Core中WebSocket握手期间的核心错误。请确保将代码示例中的命名空间和依赖项正确导入到项目中。