c#模拟命令提示板上的copy指令

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace CmdDemo
{
public class Cmd
{
public static void dir()
{
// var path = System.Windows.Forms.Application.StartupPath;
dir(System.Environment.CurrentDirectory);

    }
    public static void dir(string path)
    {          

        DirectoryInfo di = new DirectoryInfo(path);

        foreach (var d in di.GetDirectories())
        {
            Console.WriteLine("{0}\t<DIF>\t{1}",d.CreationTime,d.Name);
        }

        foreach (var f in di.GetFiles())
        {
            Console.WriteLine("{0}\t\t{1}", f.CreationTime, f.Name);
        }
        Console.WriteLine("\t\t{0} 个文件",di.GetFiles().Count());
        Console.WriteLine("\t\t{0} 个目录", di.GetDirectories().Count());
    }

    public static void cd(string path)
    {
        System.Environment.CurrentDirectory = path;
    }
    public static void del(string filePath)
    {
        if (!System.IO.File.Exists(filePath))
        {
            Console.WriteLine("找不到{0}", filePath);
            Console.WriteLine();
            return;
        }
        System.IO.File.Delete(filePath);
    }
    public static void copy(string sourceFileName,string destFileName) 
    {
         ？？？？？
    }
}

}
我刚刚学习c#，想模拟copy指令。刚刚学习还有很多不懂，上面是代码，求问号地方的代码，我也百度过，看不懂，求指导，谢谢