判断Socket是否断开的小代码

        /// <summary>
        /// 接收数据
        /// </summary>
        private void OnReceive(object ob)
        {
            var key = ClientSocket.LocalEndPoint as IPEndPoint;
            var remote = ClientSocket.RemoteEndPoint as IPEndPoint;
            while (true)
            {
                try
                {
                    if (ClientSocket == null || ClientSocket.Connected == false)  //断开
                    {
                        CloseSocket();
                        return;
                    }
                    if (ClientSocket.Poll(1000, SelectMode.SelectRead))  //断开
                    {
                        CloseSocket();
                        return;
                    }
                    var receiveBuffer = new byte[1024];
                    // 接收服务端消息
                    var receiveLength = ClientSocket.Receive(receiveBuffer);
                    if (receiveLength != 0)
                    {
                        string msg = Encoding.UTF8.GetString(receiveBuffer, 0, receiveLength);
                        WriteLog(string.Format("客户端信息――{0}:{1,-5}接受服务器消息{2}", remote.Address, remote.Port, msg));
                        EvtReceiveData(msg);
                    }