SocketException ErrorCode=0为什么会被捕获

Question

先贴代码     public byte[] SendCommand(byte[] cmd, int receiveLength)
        {
            lock (thisLock)
            {
                try
                {
                    int receiveCount = 0;
                    if (socket != null)
                    {
                        if (socket.Connected)
                        {
                            
                            byte[] value = new byte[receiveLength];
                            int length = 0;
                            socket.Send(cmd);
                            while (length < receiveLength)
                            {
                                if (receiveCount++>10)
                                {
                                    throw (new SocketException());
                                }
                                if (socket.Available > 0)
                                {
                                    int count = socket.Receive(data);
                                    if (count < 0)
                                        count = 0;
                                    errorCount = 0;
                                    Array.ConstrainedCopy(data, 0, value, length, count);
                                    length += count;
                                }
                                else
                                {
                                    System.Threading.Thread.Sleep(1);
                                }
                            }
                            return value;
                        }
                    }                    return null;
                }                catch (SocketException ex)
                {
                    System.Threading.Thread.Sleep(1000);
                    errorCount++;
                    if (errorCount > 3)
                    {
                        errorCount = 0;
                        throw new Exception("SocketError");
                    }
                    else
                    {
                        return SendCommand(cmd, receiveLength);
                    }
                }
                catch (Exception e)
                {
                    System.Threading.Thread.Sleep(1000);
                    throw e;
                }
            }
        }现在的情况是经常在catch中捕获ErrorCode=0的异常，这是怎么回事，有人知道吗