Silverlight制作逐帧动画 v2 - part2

接上一篇《Silverlight制作逐帧动画 v2 - part1》，在这里完善了一下算法，加入了fps的机制进去。

        private string[] shippics = new string[] { "Ship1/1.png", "Ship1/2.png", "Ship1/3.png", "Ship1/4.png" };
        protected DateTime lastTick;
        protected TimeSpan elapsed;

        private double lasrFrameTime = 0;
        private int currentFrame = 0;

        private double fps = 15;

        public MainPage()
        {
            InitializeComponent();
            lastTick = DateTime.Now;
            CompositionTarget.Rendering += new EventHandler(CompositionTarget_Rendering);
        }

        void CompositionTarget_Rendering(object sender, EventArgs e)
        {
            DateTime now = DateTime.Now;
            elapsed = now - lastTick;
            lastTick = DateTime.Now;

            lasrFrameTime += elapsed.TotalSeconds;

            if (lasrFrameTime >( 1 / fps))
            {
                lasrFrameTime = 0;

                currentFrame++;
                currentFrame %= shippics.Length;
                RenderShip();
            }
        }

        private void RenderShip()
        {
            var imageBrush = new ImageBrush();
            imageBrush.Stretch = Stretch.None;
            imageBrush.AlignmentX = AlignmentX.Left;
            imageBrush.AlignmentY = AlignmentY.Top;
            imageBrush.ImageSource = new BitmapImage(new Uri("/slShipAnimate;component/" + shippics[currentFrame], UriKind.Relative));
            myShip.Fill = imageBrush;
        }