MARKUS

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows;

using System.Windows.Media.Animation;

namespace ZoomAndPan

{

    public static class AnimationHelper

    {

        /// <summary>

        /// Starts an animation to a particular value on the specified dependency property.

        /// </summary>

        public static void StartAnimation(UIElement animatableElement, DependencyProperty dependencyProperty, double toValue, double animationDurationSeconds)

        {

            StartAnimation(animatableElement, dependencyProperty, toValue, animationDurationSeconds, null);

        }

        /// <summary>

        /// Starts an animation to a particular value on the specified dependency property.

        /// You can pass in an event handler to call when the animation has completed.

        /// </summary>

        public static void StartAnimation(UIElement animatableElement, DependencyProperty dependencyProperty, double toValue, double animationDurationSeconds, EventHandler completedEvent)

        {

            double fromValue = (double)animatableElement.GetValue(dependencyProperty);

            DoubleAnimation animation = new DoubleAnimation();

            animation.From = fromValue;

            animation.To = toValue;

            animation.Duration = TimeSpan.FromSeconds(animationDurationSeconds);

            animation.Completed += delegate(object sender, EventArgs e)

            {

                //

                // When the animation has completed bake final value of the animation

                // into the property.

                //

                animatableElement.SetValue(dependencyProperty, animatableElement.GetValue(dependencyProperty));

                CancelAnimation(animatableElement, dependencyProperty);

                if (completedEvent != null)

                {

                    completedEvent(sender, e);

                }

            };

            animation.Freeze();

            animatableElement.BeginAnimation(dependencyProperty, animation);

        }

        /// <summary>

        /// Cancel any animations that are running on the specified dependency property.

        /// </summary>

        public static void CancelAnimation(UIElement animatableElement, DependencyProperty dependencyProperty)

        {

            animatableElement.BeginAnimation(dependencyProperty, null);

        }

    }

}