C#把多个图片合并成一张图片。

  private void button7_Click(object sender, EventArgs e)
        {
           //把2个图片合并到一个图片中
            //文件路径
            string fs = Application.StartupPath +"\PIC\";
            //不存在文件进行创建
            if (!System.IO.Directory.Exists(fs)) System.IO.Directory.CreateDirectory(fs);
            //存储到pic文件夹中文件
            ocx.PadFileSaveAs(fs, 22, 1);
            //获取到pic下面的jpg图片
            string[] rs = System.IO.Directory.GetFiles(fs, "*.jpg");
            //最大宽度和高度
            int maL = 0, totalH = 0;

            //循环遍历获取文件的最大宽度与总高度
            for (int i = 0; i < rs.Length; i++)
            {
                Image image = Image.FromStream(new System.IO.MemoryStream(File.ReadAllBytes(rs[i])));
                if (image.Width > maL) maL = image.Width;
                totalH = totalH +  image.Height + 5;
            }
            if (totalH == 0 || maL == 0) return;
            Bitmap map = new Bitmap(maL, totalH);//定义画布
            Graphics g = Graphics.FromImage(map);//定义画笔
            g.Clear(Color.White);//把画布更改为白色
            int y=0;//y轴坐标
            for (int i = 0; i < rs.Length; i++)
            {
                Image image = Image.FromStream(new System.IO.MemoryStream(File.ReadAllBytes(rs[i])));
                g.DrawImage(image, new Point(0, y));
                y = y + image.Height + 5;//y的告诉 5是为了让画布有个缝隙
            }
            //把合并的图片进行保存为jpg格式
            map.Save(Application.StartupPath + "\1.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
            for (int i = 0; i < rs.Length; i++)
            {
                //删除原先的2个jpg图片
                File.Delete(rs[i]);
            }

        }

效果图：