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Cómo: Animar un objeto a lo largo de un trazado (animación de punto)

En este ejemplo se muestra cómo usar un PointAnimationUsingPath objeto para animar un Point objeto a lo largo de un trazado curvado.

Ejemplo

En el ejemplo siguiente, un EllipseGeometry se mueve a lo largo de un camino definido por un PathGeometry. La propiedad de la geometría de la elipse Center, que recibe un valor de Point, especifica su posición; para mover la geometría de la elipse, anima la propiedad Center. En el ejemplo se utiliza un PointAnimationUsingPath para animar la propiedad EllipseGeometry del objeto Center.

<Page 
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:PresentationOptions="http://schemas.microsoft.com/winfx/2006/xaml/presentation/options" 
  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
  mc:Ignorable="PresentationOptions">
  <Canvas Width="400" Height="400">
      
    <Path Fill="Blue" Margin="15,15,15,15">
      <Path.Data>

        <!-- The EllipseGemetry specifies the shape and position of the Ellipse. The
        Center property is animated, causing the Ellipse to animate across the screen-->
        <EllipseGeometry x:Name="MyAnimatedEllipseGeometry"
          Center="10,100" RadiusX="15" RadiusY="15" />
      </Path.Data>
      <Path.Triggers>
        <EventTrigger RoutedEvent="Path.Loaded">
          <BeginStoryboard Name="MyBeginStoryboard">
            <Storyboard>
              
              <!-- Animates the ellipse along the path. -->
              <PointAnimationUsingPath
                Storyboard.TargetName="MyAnimatedEllipseGeometry"
                Storyboard.TargetProperty="Center"
                Duration="0:0:5" 
                RepeatBehavior="Forever" >
                <PointAnimationUsingPath.PathGeometry>
                  <PathGeometry 
                    Figures="M 10,100 C 35,0 135,0 160,100 180,190 285,200 310,100"
                    PresentationOptions:Freeze="True" />
                </PointAnimationUsingPath.PathGeometry>
              </PointAnimationUsingPath>
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Path.Triggers>
    </Path>
  </Canvas>
</Page>

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

namespace SDKSample
{

    public class PointAnimationUsingPathExample : Page
    {

        public PointAnimationUsingPathExample()
        {

            // Create a NameScope for the page so that
            // we can use Storyboards.
            NameScope.SetNameScope(this, new NameScope());

            // Create the EllipseGeometry to animate.
            EllipseGeometry animatedEllipseGeometry =
                new EllipseGeometry(new Point(10, 100), 15, 15);

            // Register the EllipseGeometry's name with
            // the page so that it can be targeted by a
            // storyboard.
            this.RegisterName("AnimatedEllipseGeometry", animatedEllipseGeometry);

            // Create a Path element to display the geometry.
            Path ellipsePath = new Path();
            ellipsePath.Data = animatedEllipseGeometry;
            ellipsePath.Fill = Brushes.Blue;
            ellipsePath.Margin = new Thickness(15);

            // Create a Canvas to contain ellipsePath
            // and add it to the page.
            Canvas mainPanel = new Canvas();
            mainPanel.Width = 400;
            mainPanel.Height = 400;
            mainPanel.Children.Add(ellipsePath);
            this.Content = mainPanel;

            // Create the animation path.
            PathGeometry animationPath = new PathGeometry();
            PathFigure pFigure = new PathFigure();
            pFigure.StartPoint = new Point(10, 100);
            PolyBezierSegment pBezierSegment = new PolyBezierSegment();
            pBezierSegment.Points.Add(new Point(35, 0));
            pBezierSegment.Points.Add(new Point(135, 0));
            pBezierSegment.Points.Add(new Point(160, 100));
            pBezierSegment.Points.Add(new Point(180, 190));
            pBezierSegment.Points.Add(new Point(285, 200));
            pBezierSegment.Points.Add(new Point(310, 100));
            pFigure.Segments.Add(pBezierSegment);
            animationPath.Figures.Add(pFigure);

            // Freeze the PathGeometry for performance benefits.
            animationPath.Freeze();

            // Create a PointAnimationgUsingPath to move
            // the EllipseGeometry along the animation path.
            PointAnimationUsingPath centerPointAnimation =
                new PointAnimationUsingPath();
            centerPointAnimation.PathGeometry = animationPath;
            centerPointAnimation.Duration = TimeSpan.FromSeconds(5);
            centerPointAnimation.RepeatBehavior = RepeatBehavior.Forever;

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

            // Create a Storyboard to contain and apply the animation.
            Storyboard pathAnimationStoryboard = new Storyboard();
            pathAnimationStoryboard.RepeatBehavior = RepeatBehavior.Forever;
            pathAnimationStoryboard.AutoReverse = true;
            pathAnimationStoryboard.Children.Add(centerPointAnimation);

            // Start the Storyboard when ellipsePath is loaded.
            ellipsePath.Loaded += delegate(object sender, RoutedEventArgs e)
            {
                // Start the storyboard.
                pathAnimationStoryboard.Begin(this);
            };
        }
    }
}


Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Media.Animation
Imports System.Windows.Navigation
Imports System.Windows.Shapes


Namespace SDKSample


    Public Class PointAnimationUsingPathExample
        Inherits Page

        Public Sub New()

            ' Create a NameScope for the page so that
            ' we can use Storyboards.
            NameScope.SetNameScope(Me, New NameScope())

            ' Create the EllipseGeometry to animate.
            Dim animatedEllipseGeometry As New EllipseGeometry(New Point(10, 100), 15, 15)

            ' Register the EllipseGeometry's name with
            ' the page so that it can be targeted by a
            ' storyboard.
            Me.RegisterName("AnimatedEllipseGeometry", animatedEllipseGeometry)

            ' Create a Path element to display the geometry.
            Dim ellipsePath As New Path()
            ellipsePath.Data = animatedEllipseGeometry
            ellipsePath.Fill = Brushes.Blue
            ellipsePath.Margin = New Thickness(15)

            ' Create a Canvas to contain ellipsePath
            ' and add it to the page.
            Dim mainPanel As New Canvas()
            mainPanel.Width = 400
            mainPanel.Height = 400
            mainPanel.Children.Add(ellipsePath)
            Me.Content = mainPanel

            ' Create the animation path.
            Dim animationPath As New PathGeometry()
            Dim pFigure As New PathFigure()
            pFigure.StartPoint = New Point(10, 100)
            Dim pBezierSegment As New PolyBezierSegment()
            pBezierSegment.Points.Add(New Point(35, 0))
            pBezierSegment.Points.Add(New Point(135, 0))
            pBezierSegment.Points.Add(New Point(160, 100))
            pBezierSegment.Points.Add(New Point(180, 190))
            pBezierSegment.Points.Add(New Point(285, 200))
            pBezierSegment.Points.Add(New Point(310, 100))
            pFigure.Segments.Add(pBezierSegment)
            animationPath.Figures.Add(pFigure)

            ' Freeze the PathGeometry for performance benefits.
            animationPath.Freeze()

            ' Create a PointAnimationgUsingPath to move
            ' the EllipseGeometry along the animation path.
            Dim centerPointAnimation As New PointAnimationUsingPath()
            centerPointAnimation.PathGeometry = animationPath
            centerPointAnimation.Duration = TimeSpan.FromSeconds(5)
            centerPointAnimation.RepeatBehavior = RepeatBehavior.Forever

            ' Set the animation to target the Center property
            ' of the EllipseGeometry named "AnimatedEllipseGeometry".
            Storyboard.SetTargetName(centerPointAnimation, "AnimatedEllipseGeometry")
            Storyboard.SetTargetProperty(centerPointAnimation, New PropertyPath(EllipseGeometry.CenterProperty))

            ' Create a Storyboard to contain and apply the animation.
            Dim pathAnimationStoryboard As New Storyboard()
            pathAnimationStoryboard.RepeatBehavior = RepeatBehavior.Forever
            pathAnimationStoryboard.AutoReverse = True
            pathAnimationStoryboard.Children.Add(centerPointAnimation)

            ' Start the Storyboard when ellipsePath is loaded.
            AddHandler ellipsePath.Loaded, Sub(sender As Object, e As RoutedEventArgs) pathAnimationStoryboard.Begin(Me)
        End Sub

    End Class

End Namespace

Para obtener el ejemplo completo, vea Ejemplo de animación de trayectoria.

La versión de código del ejemplo anterior utilizó un Storyboard para animar el EllipseGeometry, aunque solo se empleó una animación. A Storyboard menudo es la manera más fácil de aplicar varias animaciones porque estas animaciones se pueden controlar mediante el mismo Storyboard. Sin embargo, una manera más sencilla de aplicar una sola animación a una propiedad cuando se usa código es usar el BeginAnimation método . Para obtener un ejemplo, vea Animar una propiedad sin usar un guión gráfico.

Consulte también