C#-多线程和Socket网络编程-C/S传输文件（完結）

//将远程连接的客户端的IP地址和Socket存入集合中
Dictionary<string, Socket> dicScoket = new Dictionary<string, Socket>();

/// <summary>
        /// 服务器给客户端发送消息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button4_Click(object sender, EventArgs e)
        {
            string str = txtMsg.Text;
            byte[] buffer = System.Text.Encoding.UTF8.GetBytes(str);
            //获取用户在下拉框选中的IP地址
            string ip = cboUsers.SelectedItem.ToString();
            dicScoket[ip].Send(buffer);
            //socketSend.Send(buffer);
        }

private void button2_Click(object sender, EventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.InitialDirectory = @"C:\Users";
            ofd.Title = "请选择要发送的文件";
            ofd.Filter = "所有文件|*.*";
            ofd.ShowDialog();
            txtPath.Text = ofd.FileName;
        }

private void button3_Click(object sender, EventArgs e)
        {
            //获得要发送的路径
            string path = txtPath.Text;
            using (FileStream fsRead=new FileStream(path,FileMode.Open,FileAccess.Read))
            {
                byte[] buffer = new byte[1024*1024*5];
                int r = fsRead.Read(buffer, 0, buffer.Length);
                List<byte> list = new List<byte>();
                list.Add(1);
                list.AddRange(buffer);
                byte[] newBuffer = list.ToArray();
                try
                {
                    dicScoket[cboUsers.SelectedItem.ToString()].Send(newBuffer, 0, r + 1, SocketFlags.None);
                }
                catch//没选IP
                {

                    MessageBox.Show("选IP啊");
                }
                
            }
        }

void Recive()
        {
            while (true)
            {
                byte[] buffer = new byte[1024 * 1024 * 3];
                //实际接收到的有效字节数
                int r = socketSend.Receive(buffer);
                //判断是否有数据没有直接结束
                if (r == 0)
                {
                    break;
                }
                //取到传过来的第一位
                int n = buffer[0];
                //根据约定的协议 判断传过来是什么
                if (n == 0)
                {
                    //发送的是文字消息
                    //GetString(buffer, 1, r-1)范围变换了
                    //buffer长度多了一个数字 那就跳过【0】从buffer【1】开始 长度是-1
                    string str = Encoding.UTF8.GetString(buffer, 1, r - 1);
                    ShowMsg(socketSend.RemoteEndPoint + ":" + str);
                }
                else if (n == 1)
                {
                    SaveFileDialog sfd = new SaveFileDialog();
                    sfd.InitialDirectory = @"C:\Users";
                    sfd.Title = "请选择要保存的文件";
                    sfd.Filter = "所有文件|*.*";
                    sfd.ShowDialog(this);
                    string path = sfd.FileName;
                    try
                    {
                        using (FileStream fsWrite = new FileStream(path, FileMode.OpenOrCreate, FileAccess.Write))
                        {
                            fsWrite.Write(buffer, 1, r - 1);
                        }

                    }
                    catch//不选文件出的问题
                    {

                        MessageBox.Show("选文件啊");
                    }
                    MessageBox.Show("保存成功");
                }
                else if (n == 2)
                {
                    ZD();
                }
            }
        }