socket网络断开

int iConn = 0;
  if (state1.sck1 != null)
  {
  if (state1.sck1.Connected)
  {
  if (state1.sck1.Poll(500, SelectMode.SelectRead))
  {
  iConn = state1.sck1.Receive(state1.acBuff);
  if (iConn == 0)
  {
  //socket连接已断开
  }
  }
  else
  {
  iConn = 1; //连接
  }
  }
  }