c# - 在 asp.net 核心服务器中处理关闭的 websocket 连接

Question

任何人都可以向我解释如何从意外终止连接的客户端中删除 websockets 吗？ 我的意思是用户以错误的方式关闭了应用程序，没有告诉服务器他们想要断开连接？ 以及您通常如何处理断开连接。

我尝试了一段代码来监听消息接收并且有一个带有 3s 的 cancellationTokenSource，所以它将检查连接是否仍然存在。当我关闭 websocket 客户端应用程序时，服务器不会转到 WebSocketState.Closed 部分，并且当取消 token 被触发时，服务器会断开与客户端的连接。我在这里做错了什么？! 提前致谢!

while (socket.State == WebSocketState.Open)
{
   var cancellationSource = new CancellationTokenSource(TimeSpan.FromMilliseconds(3000));
   buffer = new ArraySegment<byte>(new byte[4096]);

   WebSocketReceiveResult received = null;


   try
   {
       received = await socket.ReceiveAsync(buffer, cancellationSource);
   }
   catch (AggregateException e)
   {
       continue;
   }

   switch (received.MessageType)
   {
       case WebSocketMessageType.Close:

           HandleClose(socket);

       break;

       case WebSocketMessageType.Text:
           // Handle text message 

       break;
   }
}

if (socket.State == WebSocketState.Aborted)
{
    // Handle aborted
}
else if (socket.State == WebSocketState.Closed)
{
    HandleClose(socket);
}
else if (socket.State == WebSocketState.CloseReceived)
{

}
else if (socket.State == WebSocketState.CloseSent)
{
}

Answer 1

如果客户端意外关闭连接，ReceiveAsync 将抛出一个 WebSocketException。

try
{
    var received = await webSocketConnection.ReceiveAsync(...);
}
catch(WebSocketException webSocketException)
{
    if(webSocketException.WebSocketErrorCode == WebSocketError.ConnectionClosedPrematurely)
    {
        //custom logic
    }
}