C# 局域网聊天 发送信息

        //发送大量文本消息        private void sendMessage()        {            if (richTextBox_send.Text.Trim().Length==0 && richTextBox_send.Rtf.IndexOf("pict")<0)            {                MessageBox.Show("发送的消息不能为空");                return;            }                        if (Encoding.Default.GetByteCount(richTextBox_send.Text) > 1024*3)                {                    MessageBox.Show("发送的内容过长");                    return;                }            try            {                //初始化接受套接字：寻址方案，以字符流方式和Tcp通信                socketSent = new Socket(AddressFamily.InterNetwork,                               SocketType.Stream,                               ProtocolType.Tcp);                //设置目标服务器IP地址和端口                ipSent = new IPEndPoint(IPAddress.Parse(ip), 8001);                //与目标服务器进行连接                socketSent.Connect(ipSent);                                //将要发送的消息转化为字节流，然后发送                                socketSent.Send(Encoding.Default.GetBytes("MSG"));                Thread.Sleep(100);                //循环发送                //设置缓冲区为1024byte                byte[] buff = new byte[1024];                int len = 0;                MemoryStream data = new MemoryStream();                richTextBox_accept.Rtf = richTextBox_accept.Rtf.Replace(@"\f1\par", "");                richTextBox_send.SaveFile(data, RichTextBoxStreamType.RichText);                data.Position = 0;                while ((len = data.Read(buff, 0, 1024)) != 0)                {                    //按实际的字节总量发送信息                    socketSent.Send(buff, 0, len, SocketFlags.None);                    //richTextBox_accept.AppendText(Encoding.Default.GetString(buff));                }                data.Close();                data.Dispose();                socketSent.Send(Encoding.Default.GetBytes("END"));                socketSent.Close();            }            catch            {                MessageBox.Show(user + "已经下线！");                return;            }            if (richTextBox_accept.Text != "")            {                richTextBox_accept.SelectionColor = Color.Green;                richTextBox_accept.AppendText("\n" + currentUser + " " + DateTime.Now.ToString("yyyy-mm-dd hh:mm:ss") + "\n");                richTextBox_accept.SelectionColor = Color.Black;                richTextBox_accept.Select(richTextBox_accept.Text.Length, 0);                richTextBox_accept.SelectedRtf = richTextBox_send.Rtf;                richTextBox_accept.Update();                richTextBox_accept.Select(richTextBox_accept.Rtf.Length, 0);            }            else            {                richTextBox_accept.SelectionColor = Color.Green;                richTextBox_accept.AppendText(currentUser + " " + DateTime.Now.ToString("yyyy-mm-dd hh:mm:ss") + "\n");                richTextBox_accept.SelectionColor = Color.Black;                richTextBox_accept.Select(richTextBox_accept.Text.Length, 0);                richTextBox_accept.SelectedRtf = richTextBox_send.Rtf;                richTextBox_accept.Update();                richTextBox_accept.Select(richTextBox_accept.Rtf.Length, 0);            }            this.richTextBox_send.Clear();            richTextBox_accept.ScrollToCaret();        }        private void btn_close_Click(object sender, EventArgs e)        {            this.Close();        }        //组合键发送消息        private void richTextBox_send_KeyUp(object sender, KeyEventArgs e)        {            if ((Control.ModifierKeys & Keys.Control) != 0 && e.KeyCode == Keys.Enter)            {                if (radioBtn_sendStyle2.Checked)//发送模式选择为Enter+Ctrl                { sendMessage(); }            }            else if (e.KeyCode == Keys.Enter)            {                if (radioBtn_sendStyle1.Checked)//发送模式选择为Enter                {                    sendMessage();                }            }        }