Comment : animer un point à l'aide d'images clés
Cet exemple montre comment utiliser la PointAnimationUsingKeyFrames classe pour animer un Point.
Exemple
L’exemple suivant déplace une ellipse sur un tracé triangulaire. L’exemple utilise la PointAnimationUsingKeyFrames classe pour animer la Center propriété d’un EllipseGeometry. Cette animation utilise trois images clés de la manière suivante :
Au cours de la première moitié de seconde, utilise une instance de la LinearPointKeyFrame classe pour déplacer l’ellipse le long d’un chemin à un rythme stable à partir de sa position de départ. Images clés linéaires comme LinearPointKeyFrame créer une interpolation linéaire lisse entre les valeurs.
À la fin de la demi-seconde suivante, utilise une instance de la DiscretePointKeyFrame classe pour déplacer soudainement l’ellipse le long du chemin vers la position suivante. Images clés discrètes comme DiscretePointKeyFrame créer des sauts soudains entre les valeurs.
Au cours des deux dernières secondes, utilise une instance de la SplinePointKeyFrame classe pour ramener l’ellipse à sa position de départ. Trames clés spline telles que SplinePointKeyFrame créer une transition de variable entre les valeurs en fonction des valeurs de la KeySpline propriété. Dans cet exemple, l’animation commence lentement, puis accélère de façon exponentielle jusqu’à la fin du segment temporel.
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 PointAnimationUsingKeyFrames class
/// to animate the position of an object.
/// </summary>
public class PointAnimationUsingKeyFramesExample : Page
{
public PointAnimationUsingKeyFramesExample()
{
Title = "PointAnimationUsingKeyFrames 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());
// Create an EllipseGeometry.
EllipseGeometry myAnimatedEllipseGeometry =
new EllipseGeometry(new Point(200,100), 15, 15);
// Assign the EllipseGeometry a name so that
// it can be targeted by a Storyboard.
this.RegisterName(
"MyAnimatedEllipseGeometry", myAnimatedEllipseGeometry);
// Create a Path element to display the geometry.
Path aPath = new Path();
aPath.Fill = Brushes.Blue;
aPath.Data = myAnimatedEllipseGeometry;
// Create a Canvas to contain the path.
Canvas containerCanvas = new Canvas();
containerCanvas.Width = 500;
containerCanvas.Height = 400;
containerCanvas.Children.Add(aPath);
// Create a PointAnimationUsingKeyFrames to
// animate the EllipseGeometry.
PointAnimationUsingKeyFrames centerPointAnimation
= new PointAnimationUsingKeyFrames();
centerPointAnimation.Duration = TimeSpan.FromSeconds(5);
// Animate from the starting position to (100,300)
// over the first half-second using linear
// interpolation.
centerPointAnimation.KeyFrames.Add(
new LinearPointKeyFrame(
new Point(100, 300), // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(0.5))) // KeyTime
);
// Animate from (100,300) (the value of the previous key frame)
// to (400,300) at 1 second using discrete interpolation.
// Because the interpolation is discrete, the ellipse will appear
// to "jump" to (400,300) at 1 second.
centerPointAnimation.KeyFrames.Add(
new DiscretePointKeyFrame(
new Point(400, 300), // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(1))) // KeyTime
);
// Animate from (400,300) (the value of the previous key frame) to (200,100)
// over two seconds, starting at 1 second (the key time of the
// last key frame) and ending at 3 seconds.
centerPointAnimation.KeyFrames.Add(
new SplinePointKeyFrame(
new Point(200, 100), // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3)), // KeyTime
new KeySpline(0.6, 0.0, 0.9, 0.0) // KeySpline
)
);
// Set the animation to repeat forever.
centerPointAnimation.RepeatBehavior = RepeatBehavior.Forever;
// Set the animation to target the Center property
// of the object named "MyAnimatedEllipseGeometry".
Storyboard.SetTargetName(centerPointAnimation, "MyAnimatedEllipseGeometry");
Storyboard.SetTargetProperty(
centerPointAnimation, new PropertyPath(EllipseGeometry.CenterProperty));
// Create a storyboard to apply the animation.
Storyboard ellipseStoryboard = new Storyboard();
ellipseStoryboard.Children.Add(centerPointAnimation);
// Start the storyboard when the Path loads.
aPath.Loaded += delegate(object sender, RoutedEventArgs e)
{
ellipseStoryboard.Begin(this);
};
Content = containerCanvas;
}
}
}
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 PointAnimationUsingKeyFrames class
''' to animate the position of an object.
''' </summary>
Public Class PointAnimationUsingKeyFramesExample
Inherits Page
Public Sub New()
Title = "PointAnimationUsingKeyFrames 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())
' Create an EllipseGeometry.
Dim myAnimatedEllipseGeometry As New EllipseGeometry(New Point(200,100), 15, 15)
' Assign the EllipseGeometry a name so that
' it can be targeted by a Storyboard.
Me.RegisterName("MyAnimatedEllipseGeometry", myAnimatedEllipseGeometry)
' Create a Path element to display the geometry.
Dim aPath As New Path()
aPath.Fill = Brushes.Blue
aPath.Data = myAnimatedEllipseGeometry
' Create a Canvas to contain the path.
Dim containerCanvas As New Canvas()
containerCanvas.Width = 500
containerCanvas.Height = 400
containerCanvas.Children.Add(aPath)
' Create a PointAnimationUsingKeyFrames to
' animate the EllipseGeometry.
Dim centerPointAnimation As New PointAnimationUsingKeyFrames()
centerPointAnimation.Duration = TimeSpan.FromSeconds(5)
' Animate from the starting position to (100,300)
' over the first half-second using linear
' interpolation.
centerPointAnimation.KeyFrames.Add(New LinearPointKeyFrame(New Point(100, 300), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(0.5)))) ' KeyTime - Target value (KeyValue)
' Animate from (100,300) (the value of the previous key frame)
' to (400,300) at 1 second using discrete interpolation.
' Because the interpolation is discrete, the ellipse will appear
' to "jump" to (400,300) at 1 second.
centerPointAnimation.KeyFrames.Add(New DiscretePointKeyFrame(New Point(400, 300), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(1)))) ' KeyTime - Target value (KeyValue)
' Animate from (400,300) (the value of the previous key frame) to (200,100)
' over two seconds, starting at 1 second (the key time of the
' last key frame) and ending at 3 seconds.
centerPointAnimation.KeyFrames.Add(New SplinePointKeyFrame(New Point(200, 100), KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3)), New KeySpline(0.6, 0.0, 0.9, 0.0))) ' KeySpline - KeyTime - Target value (KeyValue)
' Set the animation to repeat forever.
centerPointAnimation.RepeatBehavior = RepeatBehavior.Forever
' Set the animation to target the Center property
' of the object named "MyAnimatedEllipseGeometry".
Storyboard.SetTargetName(centerPointAnimation, "MyAnimatedEllipseGeometry")
Storyboard.SetTargetProperty(centerPointAnimation, New PropertyPath(EllipseGeometry.CenterProperty))
' Create a storyboard to apply the animation.
Dim ellipseStoryboard As New Storyboard()
ellipseStoryboard.Children.Add(centerPointAnimation)
' Start the storyboard when the Path loads.
AddHandler aPath.Loaded, Sub(sender As Object, e As RoutedEventArgs) ellipseStoryboard.Begin(Me)
Content = containerCanvas
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"
Background="White" Margin="20">
<Canvas Width="400" Height="400">
<Path Fill="Blue">
<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>
<Storyboard>
<!-- Animating the Center property uses 3 KeyFrames, which animate
the ellipse allong a triangular path. -->
<PointAnimationUsingKeyFrames
Storyboard.TargetProperty="Center"
Storyboard.TargetName="MyAnimatedEllipseGeometry"
Duration="0:0:5" RepeatBehavior="Forever">
<!-- Over the first half second, Using a LinearPointKeyFrame, the ellipse
moves steadily from its starting position along the first line of the
trianglar path. -->
<LinearPointKeyFrame
KeyTime="0:0:0.5"
Value="100,300" />
<!-- Using a DiscretePointKeyFrame, the ellipse suddenly changes position
after the first second of the animation. -->
<DiscretePointKeyFrame
KeyTime="0:0:1"
Value="400,300" />
<!-- Using a SplinePointKeyFrame, the ellipse moves back to its starting
position. It moves slowly at first and then speeds up. This key frame
takes 2 seconds to complete. -->
<SplinePointKeyFrame
KeySpline="0.6,0.0 0.9,0.00"
KeyTime="0:0:3"
Value="200,100" />
</PointAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Path.Triggers>
</Path>
</Canvas>
</Page>
Pour l’exemple complet, consultez la page Animation d’image clé, exemple.
Pour assurer la cohérence avec d’autres exemples d’animation, les versions de code de cet exemple utilisent un Storyboard objet pour appliquer le PointAnimationUsingKeyFrames. Toutefois, lors de l’application d’une seule animation dans le code, il est plus simple d’utiliser la BeginAnimation méthode au lieu d’utiliser un Storyboard. Si vous voulez voir un exemple, consultez l’article Comment : animer une propriété sans utiliser de storyboard.
Voir aussi
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La source de ce contenu se trouve sur GitHub, où vous pouvez également créer et examiner les problèmes et les demandes de tirage. Pour plus d’informations, consultez notre guide du contributeur.
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