在 asp.net 核心服务器中处理关闭的 websocket 连接

Question

谁能解释一下如何从意外终止其连接的客户端中删除 websockets？我的意思是用户以一种糟糕的方式关闭了应用程序，而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 3s 的取消令牌源，所以它会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，并且当取消令牌被触发时，服务器会断开我与客户端的连接。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
    }
}