C#：一个增强的TcpClient（*）客户端演示程序及源代码下载

增强功能：

1. 独立通信线程
2. AES 256位数据加密传输

下载地址：

TcpClientPlus.zip

演示程序界面：

演示程序源代码：

using System;
using System.Net.Sockets;
using System.Windows.Forms;
using Splash.Net.Sockets;
using Splash.Windows.Forms;

namespace RunClient
{
    public partial class Form1 : Form
    {
        /// <summary>
        /// TCP连接客户端
        /// </summary>
        private TcpClientPlus tcpClient;

        public Form1()
        {
            InitializeComponent();
        }

        // 建立连接
        private void button_Connect_Click(object sender, EventArgs e)
        {
            if (tcpClient == null)
            {
                try
                {   // 建立Tcp连接
                    tcpClient = new TcpClientPlus(textBox_IP.Text, Convert.ToInt32(textBox_Port.Text));
                    button_Connect.Text = "断开连接";
                    MessageBoxPlus.Show(this, "建立连接成功！", "信息");
                }
                catch
                {
                    MessageBoxPlus.Show(this, "建立连接失败！", "信息");
                    button_Send.Enabled = false;    // 发送按钮失效
                }                
            }
            else
            {
                tcpClient.Close();
                tcpClient = null;
                button_Connect.Text = "建立连接";
                MessageBoxPlus.Show(this, "断开连接成功！", "信息");
            }
        }

        // 派发任务
        private void button_Send_Click(object sender, EventArgs e)
        {
            if (tcpClient == null || !tcpClient.Connected)
            {
                MessageBoxPlus.Show(this, "连接已中断，请重新建立连接！", "信息");
                return;
            }

            // 发送按钮失效
            button_Send.Enabled = false;

            if (String.IsNullOrEmpty(textBox_Command.Text)) return;

            // 设置通信密钥
            tcpClient.SecretKey = textBox_SecretKey.Text;           

            // 派发任务
            if (!tcpClient.ThreadTaskAllocation(HandleClientComm))
            {
                MessageBoxPlus.Show(this, "通信信道忙！", "信息");
            }
        }   

        // 清空列表
        private void button_Clear_Click(object sender, EventArgs e)
        {
            textBox_Notes.Clear();
        }

        private void textBox_Command_TextChanged(object sender, EventArgs e)
        {
            if (tcpClient != null)
            {
                if (!String.IsNullOrEmpty(textBox_Command.Text))
                {
                    button_Send.Enabled = true;
                }
            }
        }

        // 窗体关闭
        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            if (tcpClient != null)
            {
                tcpClient.Close();
            }
        }

        // 处理通信
        private void HandleClientComm(object sender, EventArgs e)
        {
            TcpClientPlus client = sender as TcpClientPlus;
            if (client != null)
            {
                try
                {
                    String Command = GetCommand();
                    String Answer;
                    client.Query(Command, out Answer);

                    SetNote(Command + "\r\n");
                    SetNote(Answer + "\r\n\r\n");
                }

                catch (Exception ex)
                {
                    Type type = ex.GetType();
                    if (type == typeof(SocketException) || type == typeof(System.IO.IOException))
                    {   // 连接中断
                        client.Close();
                        MessageBoxPlus.Show(this, "连接中断！", "信息");
                    }
                    else
                    {
                        SetNote("操作失败异常原因：" + type.Name + "\r\n\r\n");
                    }
                }
            }           
        }

        // 对 Windows 窗体控件进行线程安全调用
        private void SetNote(String text)
        {
            if (textBox_Notes.InvokeRequired)
            {
                textBox_Notes.BeginInvoke(new Action<String>((msg) =>
                {
                    textBox_Notes.AppendText(msg);
                }), text);
            }
            else
            {
                textBox_Notes.AppendText(text);
            }
        }

        // 对 Windows 窗体控件进行线程安全调用
        private String GetCommand()
        {
            if (textBox_Command.InvokeRequired)
            {
                return (String)textBox_Command.Invoke(new Func<String>(() => { return textBox_Command.Text; }));
            }
            else
            {
                return textBox_Command.Text;
            }
        }
    }
}