private void connect_Click(object sender, EventArgs e)
        {
            try
            {
                IPAddress dcip = IPAddress.Parse(dccip.Text);
                int dcport = int.Parse(dccport.Text);
                dc = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                IPEndPoint dcc = new IPEndPoint(dcip, dcport);
                dc.Connect(dcc);
            }
            catch (Exception err)
            {
                MessageBox.Show(err.Message, "连接DCC出错", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

           //下面要怎么办。。。
            
        }