【WPF学习】第五十一章 动画缓动

Storyboard x:Name="growStoryboard">
   DoubleAnimation Storyboard.TargetName="cmdGrow" Storyboard.TargetProperty="Width"
             To="400" Duration="0:0:1.5">DoubleAnimation>
Storyboard>
Storyboard x:Name="revertStoryboard">
    DoubleAnimation Storyboard.TargetName="cmdGrow" Storyboard.TargetProperty="Width"
            Duration="0:0:3">DoubleAnimation>
Storyboard>

Storyboard x:Name="growStoryboard">
    DoubleAnimation Storyboard.TargetName="cmdGrow" Storyboard.TargetProperty="Width"
                                     To="400" Duration="0:0:1.5">
           DoubleAnimation.EasingFunction>
                  ElasticEase Oscillations="10" EasingMode="EaseOut">ElasticEase>
            DoubleAnimation.EasingFunction>
      DoubleAnimation>
Storyboard>

protected override double EaseInCore(double normalizedTime)
{...}

protected override double EaseInCore(double normalizedTime)
{
   return normalizedTime;     
}

protected override double EaseInCore(double normalizedTime)
        {
            return Math.Pow(normalizedTime, 3);
        }

public class RandomJitterEase : EasingFunctionBase
    {

        // Store a random number generator.
        private Random rand = new Random();

        protected override double EaseInCore(double normalizedTime)
        {
            //To see the values add code like this:
            //System.Diagnostics.Debug.WriteLine(...);

            // Make sure there‘s no jitter in the final value.
            if (normalizedTime == 1) return 1;

            // Offset the value by a random amount.
            return Math.Abs(normalizedTime - (double)rand.Next(0, 10) / (2010 - Jitter));
        }

        public int Jitter
        {
            get { return (int)GetValue(JitterProperty); }
            set { SetValue(JitterProperty, value); }
        }

        public static readonly DependencyProperty JitterProperty =
            DependencyProperty.Register("Jitter", typeof(int), typeof(RandomJitterEase),
            new UIPropertyMetadata(1000), new ValidateValueCallback(ValidateJitter));

        private static bool ValidateJitter(object value)
        {
            int jitterValue = (int)value;
            return ((jitterValue 2000) && (jitterValue >= 0));
        }

        // This required override simply provides a live instance of your easing function.
        protected override Freezable CreateInstanceCore()
        {
            return new RandomJitterEase();
        }
    }

Window x:Class="Animation.CustomEasingFunction"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:Animation"
        Title="CustomEasingFunction" Height="300" Width="600">
    Window.Triggers>
        EventTrigger RoutedEvent="Window.Loaded">
            EventTrigger.Actions>
                BeginStoryboard>
                    Storyboard>
                        DoubleAnimation
            Storyboard.TargetName="ellipse1" Storyboard.TargetProperty="(Canvas.Left)"
            To="500" Duration="0:0:10">
                        DoubleAnimation>
                        DoubleAnimation
            Storyboard.TargetName="ellipse2" Storyboard.TargetProperty="(Canvas.Left)"
            To="500" Duration="0:0:10">
                            DoubleAnimation.EasingFunction>
                                local:RandomJitterEase EasingMode="EaseIn" Jitter="1000">local:RandomJitterEase>
                            DoubleAnimation.EasingFunction>
                        DoubleAnimation>
                    Storyboard>
                BeginStoryboard>
            EventTrigger.Actions>
        EventTrigger>
    Window.Triggers>
    Canvas Margin="10">
        Ellipse Name="ellipse1" Canvas.Left="0" Fill="Red" Width="20" Height="20">Ellipse>

        Ellipse Name="ellipse2" Canvas.Top="100" Canvas.Left="0" Fill="Red" Width="20" Height="20">Ellipse>
    Canvas>
Window>