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Cómo: Animar una geometría de rectángulo mediante fotogramas clave

En este ejemplo se muestra cómo animar la Rect propiedad de un RectangleGeometry mediante fotogramas clave.

Ejemplo

En el ejemplo siguiente se usa la clase RectAnimationUsingKeyFrames para animar la propiedad Rect de un RectangleGeometry. Esta animación usa tres fotogramas clave de la siguiente manera:

  1. Durante los primeros dos segundos, usa una instancia de la LinearRectKeyFrame clase para animar un cambio gradual en la posición, el ancho y el alto de un rectángulo. Fotogramas clave lineales como LinearRectKeyFrame crean una transición lineal suave entre valores.

  2. Durante el final de la próxima mitad de segundo, usa una instancia de la DiscreteRectKeyFrame clase para disminuir repentinamente el alto del rectángulo. Los fotogramas clave discretos como DiscreteRectKeyFrame crean cambios repentinos entre valores, es decir, la disminución en la altura se produce rápidamente y no es sutil.

  3. Durante los dos segundos finales, usa una instancia de la SplineRectKeyFrame clase para volver a cambiar el rectángulo a su tamaño y posición originales. Tramas clave spline como SplineRectKeyFrame crean una transición variable entre valores según los valores de la propiedad KeySpline. En este ejemplo, el cambio comienza lentamente y acelera exponencialmente hacia el final del segmento de tiempo.

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

namespace Microsoft.Samples.KeyFrameExamples
{
    /// <summary>
    /// This example shows how to use the RectAnimationUsingKeyFrames class to
    /// animate the position and size of a rectangle.
    /// Key frame animations enable you to create complex animations
    /// by specifying multiple destination values
    /// and controlling the animation's interpolation method.
    /// </summary>
    public class RectAnimationUsingKeyFramesExample : Page
    {
        public RectAnimationUsingKeyFramesExample()
        {
            Title = "RectAnimationUsingKeyFrames Example";
            Background = Brushes.White;
            Margin = new Thickness(20);

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

            StackPanel myStackPanel = new StackPanel();
            myStackPanel.Orientation = Orientation.Vertical;
            myStackPanel.HorizontalAlignment = HorizontalAlignment.Center;

            //Add the Path Element
            Path myPath = new Path();
            myPath.Stroke = Brushes.Black;
            myPath.Fill = Brushes.LemonChiffon;
            myPath.StrokeThickness = 1;

            // Create a RectangleGeometry to specify the Path data.
            RectangleGeometry myRectangleGeometry = new RectangleGeometry();
            myRectangleGeometry.Rect = new Rect(0, 200, 100, 100);
            myPath.Data = myRectangleGeometry;

            myStackPanel.Children.Add(myPath);

            // Assign the TranslateTransform a name so that
            // it can be targeted by a Storyboard.
            this.RegisterName(
                "AnimatedRectangleGeometry", myRectangleGeometry);

            // Create a RectAnimationUsingKeyFrames to
            // animate the RectangleGeometry.
            RectAnimationUsingKeyFrames rectAnimation
                = new RectAnimationUsingKeyFrames();
            rectAnimation.Duration = TimeSpan.FromSeconds(6);

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

            // Animate position, width, and height in first 2 seconds. LinearRectKeyFrame creates
            // a smooth, linear animation between values.
            rectAnimation.KeyFrames.Add(
                new LinearRectKeyFrame(
                    new Rect(600,50,200,50), // Target value (KeyValue)
                    KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2))) // KeyTime
                );

            // In the next half second, change height to 10. DiscreteRectKeyFrame creates a
            // sudden "jump" between values.
            rectAnimation.KeyFrames.Add(
                new DiscreteRectKeyFrame(
                    new Rect(600, 50, 200, 10), // Target value (KeyValue)
                    KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2.5))) // KeyTime
                );

            // In the final 2 seconds of the animation, go back to the starting position, width, and height.
            // Spline key frames like SplineRectKeyFrame creates a variable transition between values depending
            // on the KeySpline property. In this example, the animation starts off slow but toward the end of
            // the time segment, it speeds up exponentially.
            rectAnimation.KeyFrames.Add(
                new SplineRectKeyFrame(
                    new Rect(0, 200, 100, 100), // Target value (KeyValue)
                    KeyTime.FromTimeSpan(TimeSpan.FromSeconds(4.5)), // KeyTime
                    new KeySpline(0.6, 0.0, 0.9, 0.0) // KeySpline
                    )
                );

            // Set the animation to target the Rect property
            // of the object named "AnimatedRectangleGeometry."
            Storyboard.SetTargetName(rectAnimation, "AnimatedRectangleGeometry");
            Storyboard.SetTargetProperty(
                rectAnimation, new PropertyPath(RectangleGeometry.RectProperty));

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

            // Start the storyboard after the rectangle loads.
            myPath.Loaded += delegate(object sender, RoutedEventArgs e)
            {
                rectStoryboard.Begin(this);
            };

            Content = myStackPanel;
        }
    }
}


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

Namespace Microsoft.Samples.KeyFrameExamples
    ''' <summary>
    ''' This example shows how to use the RectAnimationUsingKeyFrames class to
    ''' animate the position and size of a rectangle.
    ''' Key frame animations enable you to create complex animations 
    ''' by specifying multiple destination values
    ''' and controlling the animation's interpolation method.
    ''' </summary>
    Public Class RectAnimationUsingKeyFramesExample
        Inherits Page
        Public Sub New()
            Title = "RectAnimationUsingKeyFrames Example"
            Background = Brushes.White
            Margin = New Thickness(20)

            ' Create a NameScope for this page so that
            ' Storyboards can be used.
            NameScope.SetNameScope(Me, New NameScope())

            Dim myStackPanel As New StackPanel()
            myStackPanel.Orientation = Orientation.Vertical
            myStackPanel.HorizontalAlignment = HorizontalAlignment.Center

            'Add the Path Element
            Dim myPath As New Path()
            myPath.Stroke = Brushes.Black
            myPath.Fill = Brushes.LemonChiffon
            myPath.StrokeThickness = 1

            ' Create a RectangleGeometry to specify the Path data.
            Dim myRectangleGeometry As New RectangleGeometry()
            myRectangleGeometry.Rect = New Rect(0, 200, 100, 100)
            myPath.Data = myRectangleGeometry

            myStackPanel.Children.Add(myPath)

            ' Assign the TranslateTransform a name so that
            ' it can be targeted by a Storyboard.
            Me.RegisterName("AnimatedRectangleGeometry", myRectangleGeometry)

            ' Create a RectAnimationUsingKeyFrames to
            ' animate the RectangleGeometry.
            Dim rectAnimation As New RectAnimationUsingKeyFrames()
            rectAnimation.Duration = TimeSpan.FromSeconds(6)

            ' Set the animation to repeat forever. 
            rectAnimation.RepeatBehavior = RepeatBehavior.Forever

            ' Animate position, width, and height in first 2 seconds. LinearRectKeyFrame creates
            ' a smooth, linear animation between values.
            rectAnimation.KeyFrames.Add(New LinearRectKeyFrame(New Rect(600,50,200,50), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2)))) ' KeyTime -  Target value (KeyValue)

            ' In the next half second, change height to 10. DiscreteRectKeyFrame creates a 
            ' sudden "jump" between values.
            rectAnimation.KeyFrames.Add(New DiscreteRectKeyFrame(New Rect(600, 50, 200, 10), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2.5)))) ' KeyTime -  Target value (KeyValue)

            ' In the final 2 seconds of the animation, go back to the starting position, width, and height.  
            ' Spline key frames like SplineRectKeyFrame creates a variable transition between values depending 
            ' on the KeySpline property. In this example, the animation starts off slow but toward the end of 
            ' the time segment, it speeds up exponentially.
            rectAnimation.KeyFrames.Add(New SplineRectKeyFrame(New Rect(0, 200, 100, 100), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(4.5)), New KeySpline(0.6, 0.0, 0.9, 0.0))) ' KeySpline -  KeyTime -  Target value (KeyValue)

            ' Set the animation to target the Rect property
            ' of the object named "AnimatedRectangleGeometry."
            Storyboard.SetTargetName(rectAnimation, "AnimatedRectangleGeometry")
            Storyboard.SetTargetProperty(rectAnimation, New PropertyPath(RectangleGeometry.RectProperty))

            ' Create a storyboard to apply the animation.
            Dim rectStoryboard As New Storyboard()
            rectStoryboard.Children.Add(rectAnimation)

            ' Start the storyboard after the rectangle loads.
            AddHandler myPath.Loaded, Sub(sender As Object, e As RoutedEventArgs) rectStoryboard.Begin(Me)

            Content = myStackPanel
        End Sub

    End Class
End Namespace

<Page  
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="ThicknessAnimationUsingKeyFrames Example">

  <StackPanel Orientation="Vertical" HorizontalAlignment="Center">

    <Path Stroke="Black" StrokeThickness="1" Fill="LemonChiffon">
      <Path.Data>
        <RectangleGeometry x:Name="myRectangleGeometry" Rect="0,200,100,100" />
      </Path.Data>
      <Path.Triggers>
        <EventTrigger RoutedEvent="Path.Loaded">
          <BeginStoryboard>
            <Storyboard>

              <!-- Animate the Rect property of the RectangleGeometry which causes the
              rectangle to animate its position as well as its width and height. -->
              <RectAnimationUsingKeyFrames
                Storyboard.TargetName="myRectangleGeometry"
                Storyboard.TargetProperty ="Rect"
                Duration="0:0:6" FillBehavior="HoldEnd" RepeatBehavior="Forever">

                <!-- Animate position, width, and height in first 2 seconds. LinearRectKeyFrame creates
                a smooth, linear animation between values. -->
                <LinearRectKeyFrame Value="600,50,200,50" KeyTime="0:0:2" />

                <!-- In the next half second, change height to 10. DiscreteRectKeyFrame creates a 
                sudden "jump" between values. -->
                <DiscreteRectKeyFrame Value="600,50,200,10" KeyTime="0:0:2.5" />

                <!-- In the final 2 seconds of the animation, go back to the starting position, width, and height.  
                Spline key frames like SplineRectKeyFrame creates a variable transition between values depending 
                on the KeySpline property. In this example, the animation starts off slow but toward the end of 
                the time segment, it speeds up exponentially.-->
                <SplineRectKeyFrame Value="0,200,100,100" KeyTime="0:0:4.5" KeySpline="0.6,0.0 0.9,0.00"  />
              </RectAnimationUsingKeyFrames>
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Path.Triggers>
    </Path>

  </StackPanel>
</Page>

Para ver el ejemplo completo, consulte Ejemplo de animación de cuadros clave.

Consulte también