>>331
private bool mIsBusy = false;
private async void StartSlideShow()
{
　　if (mIsBusy) return;
　　mIsBusy = true;
　　var dir = @"C:\Windows\Web\Wallpaper\Theme2";
　　var names = new[] { "img7.jpg", "img8.jpg", "img7.jpg", "img8.jpg", "img7.jpg", "img8.jpg" };
　　foreach (var name in names)
　　{
　　　　var path = System.IO.Path.Combine(dir, name);
　　　　pictureBox1.ImageLocation = path;
　　　　await Task.Delay(500);
　　}
　　mIsBusy = false;
}