批量重命名文件

        private void button1_Click(object sender, EventArgs e)
        {
            string directoryName = textBox1.Text.Trim();    //文件夹路径
            string[] files = Directory.GetFiles(directoryName); 
            foreach (string sDirectory in files)
            {
                string fileName = Path.GetFileName(sDirectory);     //旧文件名
                string newFileName = fileName.Split('_')[2];        //新文件名
                string sNewDirectory = Path.Combine(directoryName, newFileName);    //文件夹路径+新文件名
                Directory.Move(sDirectory, sNewDirectory);
            }
        }