如何解决winform窗体全屏显示gif卡成单帧？

我想在winform窗体背景上全屏显示gif，卡成单帧怎么解决？求解答
代码如下：

Task.Run(() =>
{
    Bitmap animatedGif = new Bitmap(Application.StartupPath + "bone.gif"/*图片路径*/);
    Graphics g = this.CreateGraphics();
    int PropertyTagFrameDelay = 0x5100;
    PropertyItem propItem = animatedGif.GetPropertyItem(PropertyTagFrameDelay);
    byte[] bytes = propItem.Value;
    FrameDimension frameDimension = new FrameDimension(animatedGif.FrameDimensionsList[0]);
    int frameCount = animatedGif.GetFrameCount(FrameDimension.Time);
    while (true)
    {
        for (int i = 0; i <= animatedGif.GetFrameCount(frameDimension) - 1; i++)
        {
            this.BeginInvoke(new Action(() =>
            {
                animatedGif.SelectActiveFrame(frameDimension, i);
                g.DrawImage(animatedGif, 0, 0, f1.Width, f1.Height);
            }));
            Thread.Sleep(100);
        }
    }
});

• 你可以参考下这篇文章：c# winform 显示动态gif图片的简单方法

嵌套一个webbrowser，利用wb去显示gif图像。