代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;

namespace PractiseCCode
{
    public partial class FrmFolder : Form
    {
        public FrmFolder()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            //复制所选目录下所有文件夹和文件
            string path = this.textBox1.Text.Trim();
            string newpath=this.textBox2.Text.Trim();
            copydirectory(path, newpath);
            MessageBox.Show("ok!");

        }
        private static void copydirectory(string oldpath, string newpath)
        {
            DirectoryInfo olddir = new DirectoryInfo(oldpath);
            DirectoryInfo newdir = new DirectoryInfo(newpath);
            if (!olddir.Exists)
            {
                MessageBox.Show("选择路径不能为空！");
            }
            if (!newdir.Exists)
            { //若目标路径没有文件夹，就新建一个
                Directory.CreateDirectory(newpath);
            }
            FileInfo[] files = olddir.GetFiles(); //找出目录下所有文件
            foreach (FileInfo fi in files)
            {
                File.Copy(fi.FullName, newpath + "\\" + fi.Name,true);
            }
            DirectoryInfo[] dirs = olddir.GetDirectories(); //找出目录下的所有文件夹
            foreach ( DirectoryInfo di in dirs)
            {
                copydirectory(di.FullName, newpath +"\\"+ di.Name);
            }
        
        }

        private void button1_Click(object sender, EventArgs e)
        {
            FolderBrowserDialog fbdlog = new FolderBrowserDialog();
            DialogResult dr = fbdlog.ShowDialog();
            if (dr == DialogResult.OK)
            {
                textBox1.Text = fbdlog.SelectedPath;
            }
        }
        
    }
}