WPF Animation Helpers when switching UI

AnimationHelpers.cs

using System;
using System.Windows;
using System.Windows.Media;
using System.Windows.Media.Animation;

public class AnimationHelpers
{
    public static void Fade(UIElement incoming, UIElement outgoing, int seconds)
    {
        Storyboard story = new Storyboard();
        story.Children.Add(CreateAnimation(incoming, 0.0, 1.0, "Opacity", seconds));
        story.Children.Add(CreateAnimation(outgoing, 1.0, 0.0, "Opacity", seconds));
        story.Begin();
    }

    public static void SlideLeft(UIElement incoming, UIElement outgoing, int seconds)
    {
        Move(incoming, outgoing, seconds, "X", incoming.RenderSize.Width, 0, 0, -outgoing.RenderSize.Width);
    }

    public static void SlideRight(UIElement incoming, UIElement outgoing, int seconds)
    {
        Move(incoming, outgoing, seconds, "X", -incoming.RenderSize.Width, 0, 0, outgoing.RenderSize.Width);
    }

    public static void SlideDown(UIElement incoming, UIElement outgoing, int seconds)
    {
        Move(incoming, outgoing, seconds, "Y", -incoming.RenderSize.Height, 0, 0, outgoing.RenderSize.Height);
    }

    public static void SlideUp(UIElement incoming, UIElement outgoing, int seconds)
    {
        Move(incoming, outgoing, seconds, "Y", incoming.RenderSize.Height, 0, 0, -outgoing.RenderSize.Height);
    }

    private static DoubleAnimation CreateAnimation(UIElement dst, double from, double to, string propertyPath, int seconds)
    {
        DoubleAnimation anim = new DoubleAnimation(from, to, TimeSpan.FromSeconds(seconds));
        anim.FillBehavior = FillBehavior.HoldEnd;
        Storyboard.SetTarget(anim, dst);
        Storyboard.SetTargetProperty(anim, new PropertyPath(propertyPath));
        return anim;
    }

    private static void Move(UIElement incoming, UIElement outgoing, int seconds, string xOrY, double inFrom, double inTo, double outFrom, double outTo)
    {
        Storyboard story = new Storyboard();

        TranslateTransform incomingTransform = new TranslateTransform();
        incoming.RenderTransform = incomingTransform;
        story.Children.Add(CreateAnimation(incoming, inFrom, inTo, "RenderTransform.(TranslateTransform." + xOrY + ")", seconds));

        TranslateTransform outgoingTransform = new TranslateTransform();
        outgoing.RenderTransform = outgoingTransform;
        story.Children.Add(CreateAnimation(outgoing, outFrom, outTo, "RenderTransform.(TranslateTransform." + xOrY + ")", seconds));

        story.Begin();
    }

    public static void Size(UIElement incoming, UIElement outgoing, int seconds)
    {
        Storyboard story = new Storyboard();

        ScaleTransform incomingTransform = new ScaleTransform();
        incomingTransform.CenterX = incoming.RenderSize.Width / 2;
        incomingTransform.CenterY = incoming.RenderSize.Height/ 2;
        incoming.RenderTransform = incomingTransform;
        story.Children.Add(CreateAnimation(incoming, 0.0, 1.0, "RenderTransform.(ScaleTransform.ScaleX)", seconds));
        story.Children.Add(CreateAnimation(incoming, 0.0, 1.0, "RenderTransform.(ScaleTransform.ScaleY)", seconds));

        ScaleTransform outgoingTransform = new ScaleTransform();
        outgoingTransform.CenterX = outgoing.RenderSize.Width / 2;
        outgoingTransform.CenterY = outgoing.RenderSize.Height / 2;
        outgoing.RenderTransform = outgoingTransform;
        story.Children.Add(CreateAnimation(outgoing, 1.0, 0.0, "RenderTransform.(ScaleTransform.ScaleX)", seconds));
        story.Children.Add(CreateAnimation(outgoing, 1.0, 0.0, "RenderTransform.(ScaleTransform.ScaleY)", seconds));

        story.Begin();
    }

    public static void SqueezeDown(UIElement incoming, UIElement outgoing, int seconds)
    {
        Storyboard story = new Storyboard();

        TranslateTransform incomingTransform = new TranslateTransform();
        incoming.RenderTransform = incomingTransform;
        story.Children.Add(CreateAnimation(incoming, -incoming.RenderSize.Height, 0, "RenderTransform.(TranslateTransform.Y)", seconds));

        ScaleTransform outgoingTransform = new ScaleTransform();
        outgoingTransform.CenterY = outgoing.RenderSize.Height;
        outgoing.RenderTransform = outgoingTransform;
        story.Children.Add(CreateAnimation(outgoing, 1.0, 0.0, "RenderTransform.(ScaleTransform.ScaleY)", seconds));

        story.Begin();
    }
}