private ChangeTypeEnum cte;
        public ChangeTime()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            FolderBrowserDialog path = new FolderBrowserDialog();
            path.ShowDialog();
            this.textBox1.Text = path.SelectedPath;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(comboBox1.Text))
            {
                MessageBox.Show("请选类型");
                return;
            }
            cte = (ChangeTypeEnum)Enum.Parse(typeof(ChangeTypeEnum), comboBox1.Text);
            //获取需要修改的时间
            DateTime dt = dateTimePicker1.Value.Date;
            dt.AddHours((double)numericUpDown1.Value);
            dt.AddMinutes((double)numericUpDown2.Value);
            dt.AddSeconds((double)numericUpDown3.Value);
            GetFilesByDir(this.textBox1.Text);
            foreach (FileInfo fi in fileInfos)
            {
                switch (cte)
                {
                    case ChangeTypeEnum.创建日期:
                        listBox1.Items.Add($"文件名{fi.Name} 原始时间：{fi.CreationTime.ToString()}修改后时间:{dt.ToString()}");
                        fi.CreationTime = dt;
                        break;
                    case ChangeTypeEnum.修改时间:
                        listBox1.Items.Add($"文件名{fi.Name} 原始时间：{fi.CreationTime.ToString()}修改后时间:{dt.ToString()}");
                        fi.LastWriteTimeUtc = dt;
                        break;
                    default:
                        fi.CreationTime = dt;
                        fi.LastWriteTimeUtc = dt;
                        break;
                } 
            }
            MessageBox.Show("修改完成");

        }