C# 批量修改文件名

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;
using System.Text.RegularExpressions;

namespace WindowsFormsAppSocket
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        //批量修改文件名
        private void button1_Click(object sender, EventArgs e)
        {
            string path = @"H:\Resource\动漫\火影忍者";

            DirectoryInfo dicInfo = new DirectoryInfo(path);

            FileInfo[] files = dicInfo.GetFiles();

            foreach (var item in files)
            {
                //MessageBox.Show(item.FullName);

                string fullname = item.FullName;
                string filename = Path.GetFileName(fullname);
                string extension = Path.GetExtension(fullname).ToLower();
                if (extension == ".mp4")
                {
                    Regex reg = new Regex("[0-9-]+");
                    string match = reg.Match(filename).ToString();

                    string newFilename = match + extension;

                    string newPath = path + "\\test\\";

                    if (!Directory.Exists(newPath))
                    {
                        Directory.CreateDirectory(newPath);
                    }

                    item.MoveTo(newPath + newFilename);

                    //MessageBox.Show(newPath);
                }
                else
                {
                    //item.Delete();
                }

            }

            MessageBox.Show("修改视频文件成功！！！！");

        }
    }
}