Comment : animer un objet sur un tracé (animation de matrice avec accumulation d'offsets)
Cet exemple montre comment utiliser la classe MatrixAnimationUsingPath pour animer un objet sur un tracé et faire en sorte que cette animation accumule ses valeurs offset lorsqu'elle est répétée.
Exemple
L'exemple suivant utilise l'objet MatrixAnimationUsingPath pour animer la propriété Matrix d'un MatrixTransform appliqué à un bouton. Par conséquent, un bouton est déplacé le long d'un tracé courbé.
De plus, l'exemple affecte true à la propriété IsOffsetCumulative, ce qui entraîne l'accumulation de l'offset de la matrice animée lorsque l'animation est répétée. Du fait de l'accumulation d'offsets, le bouton se déplace sur l'écran lorsque l'animation est répétée, plutôt que d'être réinitialisé à la position de départ.
<Page
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml" Margin="20"
xmlns:PresentationOptions="https://schemas.microsoft.com/winfx/2006/xaml/presentation/options"
xmlns:mc="https://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="PresentationOptions">
<Canvas Width="400" Height="400">
<!-- The Button that is animated across the screen by animating
the MatrixTransform applied to the button. -->
<Button MinWidth="100" Content="A Button">
<Button.RenderTransform>
<MatrixTransform x:Name="myMatrixTransform">
<MatrixTransform.Matrix >
<Matrix />
</MatrixTransform.Matrix>
</MatrixTransform>
</Button.RenderTransform>
<Button.Triggers>
<EventTrigger RoutedEvent="Button.Click">
<BeginStoryboard>
<Storyboard>
<MatrixAnimationUsingPath
Storyboard.TargetName="myMatrixTransform"
Storyboard.TargetProperty="Matrix"
IsOffsetCumulative="True"
Duration="0:0:5"
RepeatBehavior="2x">
<MatrixAnimationUsingPath.PathGeometry>
<PathGeometry
Figures="M 10,100 C 35,0 135,0 160,100 180,190 285,200 310,100"
PresentationOptions:Freeze="True" />
</MatrixAnimationUsingPath.PathGeometry>
</MatrixAnimationUsingPath>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
</Canvas>
</Page>
Imports System
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
''' <summary>
''' Shows how to use the MatrixAnimationUsingPath.IsOffsetCumulative
''' property to make a MatrixAnimatioinUsingPath accumulate
''' its values when it repeats.
''' </summary>
Public Class MatrixAnimationUsingPathExampleOffsetCumulative
Inherits Page
Public Sub New()
Me.Margin = New Thickness(20)
' Create a NameScope for the page so that
' we can use Storyboards.
NameScope.SetNameScope(Me, New NameScope())
' Create a button.
Dim aButton As New Button()
aButton.MinWidth = 100
aButton.Content = "A Button"
' Create a MatrixTransform. This transform
' will be used to move the button.
Dim buttonMatrixTransform As New MatrixTransform()
aButton.RenderTransform = buttonMatrixTransform
' Register the transform's name with the page
' so that it can be targeted by a Storyboard.
Me.RegisterName("ButtonMatrixTransform", buttonMatrixTransform)
' Create a Canvas to contain the button
' and add it to the page.
' Although this example uses a Canvas,
' any type of panel will work.
Dim mainPanel As New Canvas()
mainPanel.Width = 400
mainPanel.Height = 400
mainPanel.Children.Add(aButton)
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 MatrixAnimationUsingPath to move the
' button along the path by animating
' its MatrixTransform.
Dim matrixAnimation As New MatrixAnimationUsingPath()
matrixAnimation.PathGeometry = animationPath
' Set IsOffsetCumulative to true so that the animation
' values accumulate when its repeats.
matrixAnimation.IsOffsetCumulative = True
matrixAnimation.Duration = TimeSpan.FromSeconds(5)
matrixAnimation.RepeatBehavior = New RepeatBehavior(2)
' Set the animation to target the Matrix property
' of the MatrixTransform named "ButtonMatrixTransform".
Storyboard.SetTargetName(matrixAnimation, "ButtonMatrixTransform")
Storyboard.SetTargetProperty(matrixAnimation, New PropertyPath(MatrixTransform.MatrixProperty))
' Create a Storyboard to contain and apply the animation.
Dim pathAnimationStoryboard As New Storyboard()
pathAnimationStoryboard.Children.Add(matrixAnimation)
' Start the animation when the button is clicked.
AddHandler aButton.Click, Sub(sender As Object, e As RoutedEventArgs) pathAnimationStoryboard.Begin(Me)
End Sub
End Class
End Namespace
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
{
/// <summary>
/// Shows how to use the MatrixAnimationUsingPath.IsOffsetCumulative
/// property to make a MatrixAnimatioinUsingPath accumulate
/// its values when it repeats.
/// </summary>
public class MatrixAnimationUsingPathExampleOffsetCumulative : Page
{
public MatrixAnimationUsingPathExampleOffsetCumulative()
{
this.Margin = new Thickness(20);
// Create a NameScope for the page so that
// we can use Storyboards.
NameScope.SetNameScope(this, new NameScope());
// Create a button.
Button aButton = new Button();
aButton.MinWidth = 100;
aButton.Content = "A Button";
// Create a MatrixTransform. This transform
// will be used to move the button.
MatrixTransform buttonMatrixTransform = new MatrixTransform();
aButton.RenderTransform = buttonMatrixTransform;
// Register the transform's name with the page
// so that it can be targeted by a Storyboard.
this.RegisterName("ButtonMatrixTransform", buttonMatrixTransform);
// Create a Canvas to contain the button
// and add it to the page.
// Although this example uses a Canvas,
// any type of panel will work.
Canvas mainPanel = new Canvas();
mainPanel.Width = 400;
mainPanel.Height = 400;
mainPanel.Children.Add(aButton);
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 MatrixAnimationUsingPath to move the
// button along the path by animating
// its MatrixTransform.
MatrixAnimationUsingPath matrixAnimation =
new MatrixAnimationUsingPath();
matrixAnimation.PathGeometry = animationPath;
// Set IsOffsetCumulative to true so that the animation
// values accumulate when its repeats.
matrixAnimation.IsOffsetCumulative = true;
matrixAnimation.Duration = TimeSpan.FromSeconds(5);
matrixAnimation.RepeatBehavior = new RepeatBehavior(2);
// Set the animation to target the Matrix property
// of the MatrixTransform named "ButtonMatrixTransform".
Storyboard.SetTargetName(matrixAnimation, "ButtonMatrixTransform");
Storyboard.SetTargetProperty(matrixAnimation,
new PropertyPath(MatrixTransform.MatrixProperty));
// Create a Storyboard to contain and apply the animation.
Storyboard pathAnimationStoryboard = new Storyboard();
pathAnimationStoryboard.Children.Add(matrixAnimation);
// Start the animation when the button is clicked.
aButton.Click += delegate(object sender, RoutedEventArgs e)
{
// Start the storyboard.
pathAnimationStoryboard.Begin(this);
};
}
}
}
Notez que, bien que la propriété IsOffsetCumulative entraîne l'accumulation de valeurs offset lors des répétitions, elle n'entraîne pas l'accumulation des valeurs de rotation. Pour entraîner l'accumulation des valeurs de rotation, affectez true aux propriétés DoesRotateWithTangent et IsAngleCumulative de l'animation.
Pour l'exemple complet, consultez Animation de tracés, exemple. Pour obtenir un exemple indiquant comment animer une valeur Matrix sur un chemin sans accumulation d'offsets, consultez Comment : animer un objet sur un tracé (animation de matrice).