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Procedura: animare la proprietà Size di un ArcSegment

Aggiornamento: novembre 2007

In questo esempio viene illustrato come animare la proprietà Size di un oggetto ArcSegment.

Esempio

Nell'esempio seguente viene creato un oggetto ArcSegment che anima Size quando viene caricato sullo schermo.

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

namespace SDKSamples
{
    public class SizeAnimationExample : Page
    {
        public SizeAnimationExample()
        {

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

            // Create an ArcSegment to define the geometry of the path.
            // The Size property of this segment is animated.
            ArcSegment myArcSegment = new ArcSegment();
            myArcSegment.Size = new Size(90, 80);
            myArcSegment.SweepDirection = SweepDirection.Clockwise;
            myArcSegment.Point = new Point(500, 200);

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

            PathSegmentCollection myPathSegmentCollection = new PathSegmentCollection();
            myPathSegmentCollection.Add(myArcSegment);

            // Create a PathFigure to be used for the PathGeometry of myPath.
            PathFigure myPathFigure = new PathFigure();

            // Set the starting point for the PathFigure specifying that the
            // geometry starts at point 100,200.
            myPathFigure.StartPoint = new Point(100, 200);

            myPathFigure.Segments = myPathSegmentCollection;

            PathFigureCollection myPathFigureCollection = new PathFigureCollection();
            myPathFigureCollection.Add(myPathFigure);

            PathGeometry myPathGeometry = new PathGeometry();
            myPathGeometry.Figures = myPathFigureCollection;

            // Create a path to draw a geometry with.
            Path myPath = new Path();
            myPath.Stroke = Brushes.Black;
            myPath.StrokeThickness = 1;

            // specify the shape of the path using the path geometry.
            myPath.Data = myPathGeometry;

            SizeAnimation mySizeAnimation = new SizeAnimation();
            mySizeAnimation.Duration = TimeSpan.FromSeconds(2);

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

            // Set the From and To properties of the animation.
            mySizeAnimation.From = new Size(90, 80);
            mySizeAnimation.To = new Size(200, 200);

            // Set the animation to target the Size property
            // of the object named "myArcSegment."
            Storyboard.SetTargetName(mySizeAnimation, "myArcSegment");
            Storyboard.SetTargetProperty(
                mySizeAnimation, new PropertyPath(ArcSegment.SizeProperty));

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

            // 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;
        }
    }
}
<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation" 
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml" >
    <Canvas HorizontalAlignment="Left" Margin="0" >

      <!-- Create an arc on the screen that animates its size when it loads. -->
      <Path Stroke="Black" StrokeThickness="2" >
        <Path.Data>
          <PathGeometry>
            <PathGeometry.Figures>
              <PathFigureCollection>
                <PathFigure StartPoint="100,200">
                  <PathFigure.Segments>
                    <PathSegmentCollection>
                      <ArcSegment x:Name="myArcSegment" Size="90,80" 
                      SweepDirection="Clockwise"  Point="500,200" />
                    </PathSegmentCollection>
                  </PathFigure.Segments>
                </PathFigure>
              </PathFigureCollection>
            </PathGeometry.Figures>
          </PathGeometry>
        </Path.Data>
        <Path.Triggers>
          <EventTrigger RoutedEvent="Path.Loaded">
            <BeginStoryboard Name="myBeginStoryBoard">
              <Storyboard>

                <!-- Animate the size of the ArcSegment to a width and height of 200. -->
                <SizeAnimation
                Storyboard.TargetName="myArcSegment"
                Storyboard.TargetProperty="Size"
                From="90,80"
                To="200,200"
                Duration="0:0:2" />

              </Storyboard>
            </BeginStoryboard>
          </EventTrigger>
        </Path.Triggers>
      </Path>
    </Canvas>

</Page>

Per ulteriori esempi di geometria e animazione, vedere Esempio di geometrie.

Vedere anche

Concetti

Cenni preliminari sull'animazione

Cenni preliminari sulle classi Geometry

Riferimenti

Size

ArcSegment

Altre risorse

Procedure relative agli oggetti Geometry

Esempi relativi agli oggetti Geometry

Animazione e sistema di temporizzazione

Procedure relative all'animazione e al sistema di temporizzazione

Esempi di animazione e sistema di temporizzazione