如何在.NET 2.0中打开多帧TIFF图像格式图像？

这是我使用的:

private List GetAllPages(string file)
{
    List images = new List();
    Bitmap bitmap = (Bitmap)Image.FromFile(file);
    int count = bitmap.GetFrameCount(FrameDimension.Page);
    for (int idx = 0; idx < count; idx++)
    {
        // save each frame to a bytestream
        bitmap.SelectActiveFrame(FrameDimension.Page, idx);
        MemoryStream byteStream = new MemoryStream();
        bitmap.Save(byteStream, ImageFormat.Tiff);

        // and then create a new Image from it
        images.Add(Image.FromStream(byteStream));
    }
    return images;
}