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PointAnimation Class

Animates the value of a Point property between two target values using linear interpolation over a specified Duration.

Namespace:  System.Windows.Media.Animation
Assembly:  PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation

public class PointAnimation : PointAnimationBase
<PointAnimation .../>

An animation updates the value of a property over a period of time. An animation effect can be subtle, such as moving a Shape a few pixels left and right, or dramatic, such as enlarging an object to 200 times its original size while spinning it and changing its color. To create an animation in Windows Presentation Foundation (WPF), you must associate an animation with an object's property value.

Target Values

The PointAnimation class creates a transition between two target values. To set its target values, use its From, To, and By properties.  The following table summarizes how the From, To, and By properties may be used together or separately to determine an animation's target values.

Properties specified

Resulting behavior

From

The animation progresses from the value specified by the From property to the base value of the property being animated or to a previous animation's output value, depending on how the previous animation is configured.

From and To

The animation progresses from the value specified by the From property to the value specified by the To property.

From and By

The animation progresses from the value specified by the From property to the value specified by the sum of the From and By properties.

To

The animation progresses from the animated property's base value or a previous animation's output value to the value specified by the To property.

By

The animation progresses from the base value of the property being animated or a previous animation's output value to the sum of that value and the value specified by the By property.

NoteNote:

If you set both the To and By properties, the To property takes precedence and the By property is ignored.

To use other interpolation methods or animate between more than two target values, use a PointAnimationUsingKeyFrames object.

For information about applying multiple animations to a single property, see Key-Frame Animations Overview.

Freezable Features

Because the PointAnimation class inherits from Freezable, PointAnimation objects gain several special features, which include the following: they can be declared as resources, shared among multiple objects, made read-only to improve performance, cloned, and made thread-safe. For more information about the different features provided by Freezable objects, see the Freezable Objects Overview.

This example shows how to use the PointAnimation class to animate an object along a Path.

The following example moves an ellipse along a Path from one point on the screen to another. The example animates the position of an EllipseGeometry by using PointAnimation to animate the Center property.

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Shapes;
using System.Windows.Media.Animation;
using System.Windows.Media;

namespace SDKSamples
{
    // This example shows how to use PointAnimation to animate the 
    // position of an ellipse by animating the Center property of an  
    // EllipseGeometry. PointAnimation is used because the Center property 
    // takes a Point value. 
    public class PointAnimationExample : Page
    {
        public PointAnimationExample()
        {

            // Create a NameScope for this page so that 
            // Storyboards can be used.
            NameScope.SetNameScope(this, new NameScope());

            EllipseGeometry myEllipseGeometry = new EllipseGeometry();
            myEllipseGeometry.Center = new Point(200, 100);
            myEllipseGeometry.RadiusX = 15;
            myEllipseGeometry.RadiusY = 15;

            // Assign the EllipseGeometry a name so that 
            // it can be targeted by a Storyboard. 
            this.RegisterName(
                "MyAnimatedEllipseGeometry", myEllipseGeometry);

            Path myPath = new Path();
            myPath.Fill = Brushes.Blue;
            myPath.Margin = new Thickness(15);
            myPath.Data = myEllipseGeometry;

            PointAnimation myPointAnimation = new PointAnimation();
            myPointAnimation.Duration = TimeSpan.FromSeconds(2);

            // Set the animation to repeat forever. 
            myPointAnimation.RepeatBehavior = RepeatBehavior.Forever;

            // Set the From and To properties of the animation.
            myPointAnimation.From = new Point(200, 100);
            myPointAnimation.To = new Point(450, 250);

            // Set the animation to target the Center property 
            // of the object named "MyAnimatedEllipseGeometry."
            Storyboard.SetTargetName(myPointAnimation, "MyAnimatedEllipseGeometry");
            Storyboard.SetTargetProperty(
                myPointAnimation, new PropertyPath(EllipseGeometry.CenterProperty));

            // Create a storyboard to apply the animation.
            Storyboard ellipseStoryboard = new Storyboard();
            ellipseStoryboard.Children.Add(myPointAnimation);

            // Start the storyboard when the Path loads.
            myPath.Loaded += delegate(object sender, RoutedEventArgs e)
            {
                ellipseStoryboard.Begin(this);
            };

            Canvas containerCanvas = new Canvas();
            containerCanvas.Children.Add(myPath);

            Content = containerCanvas;
        }

    }
}
<!-- This example shows how to use PointAnimation to animate the
position of an ellipse by animating the Center property of an 
EllipseGeometry. PointAnimation is used because the Center property
takes a Point value. -->
<Page  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Canvas>
      <Path Fill="Blue" Margin="15,15,15,15">
        <Path.Data>

          <!-- Describes an ellipse. -->
          <EllipseGeometry x:Name="MyAnimatedEllipseGeometry"
            Center="200,100" RadiusX="15" RadiusY="15" />
        </Path.Data>
        <Path.Triggers>
          <EventTrigger RoutedEvent="Path.Loaded">
            <BeginStoryboard Name="MyBeginStoryboard">
              <Storyboard>

                <!-- Animate the Center property so that the ellipse animates from 
                one point on the screen to another. -->
                <PointAnimation
                Storyboard.TargetProperty="Center"
                Storyboard.TargetName="MyAnimatedEllipseGeometry"
                Duration="0:0:2" From="200,100" To="450,250" RepeatBehavior="Forever" />
              </Storyboard>
            </BeginStoryboard>
          </EventTrigger>
        </Path.Triggers>
      </Path>
    </Canvas>
</Page>

More Code

How to: Animate an EllipseGeometry This example shows how to animate a Geometry within a Path element. In the following example, a PointAnimation is used to animate the Center of an EllipseGeometry.
How to: Animate a Property Without Using a Storyboard This example shows one way to apply an animation to a property without using a Storyboard.
How to: Animate a Property by Using a Storyboard This example shows how to use a Storyboard to animate properties. To animate a property by using a Storyboard, create an animation for each property that you want to animate and also create a Storyboard to contain the animations.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0

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