C#实现合并多张图片为GIF动态图

string newPath = Application.StartupPath + "\\new.gif";
        public Form1()
        {
            InitializeComponent();
            textBox1.Text = Application.StartupPath + "\\images\\";
        }

        private void btn_merge_Click(object sender, EventArgs e)
        {
            List<string> imgs = Directory.GetFiles(textBox1.Text, "*.jpg").ToList();
            imgs.Sort((a, b) =>
            {
                string reg = "[0-9]+";
                int a_index = int.Parse(Regex.Match(a, reg).Value);
                int b_index = int.Parse(Regex.Match(b, reg).Value);
                return a_index > b_index ? 1 : a_index < b_index ? -1 : 0;
            });
            AnimatedGifEncoder ae = new AnimatedGifEncoder();
            ae.Start(newPath);
            ae.SetDelay(120);   // 延迟间隔
            ae.SetRepeat(0);  //-1:不循环,0:循环播放
            for (int i = 0; i < imgs.Count; i++)
            {
                ae.AddFrame(Image.FromFile(imgs[i]));
            }
            ae.Finish();
            MessageBox.Show("处理完成,请点击预览查看");
        }

        private void btn_preview_Click(object sender, EventArgs e)
        {
            Image img = Image.FromFile(newPath);
            lb_img.Image = img;
        }