基于C#实现12306的动态验证码变成静态验证码的方法

Image imgGif = Image.FromFile(Application.StartupPath + @"\getPassCodeNew.gif");
FrameDimension ImgFrmDim = new FrameDimension(imgGif.FrameDimensionsList[0]);
System.Drawing.Bitmap bp = new Bitmap(imgGif.Size.Width, imgGif.Size.Height);
int nFrameCount = imgGif.GetFrameCount(ImgFrmDim);
for (int i = 0; i < nFrameCount; i++)
{
imgGif.SelectActiveFrame(ImgFrmDim, i);
System.Drawing.Bitmap nbp = new Bitmap(imgGif);
Color dd = nbp.GetPixel(1, 1);
if (i == 0)
{
for (int x = 0; x < nbp.Width; x++)
{
for (int y = 0; y < nbp.Height; y++)
{
bp.SetPixel(x, y, dd);
}
}
}
for (int x = 0; x < nbp.Width; x++)
{
for (int y = 0; y < nbp.Height; y++)
{
Color c = nbp.GetPixel(x, y);
if (c == dd) continue;
bp.SetPixel(x, y, c);
}
}
}
bp.Save(Application.StartupPath + @"\Frame.jpg", ImageFormat.Bmp);