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Anvisningar: Animera en dubbel med hjälp av nyckelramar

Det här exemplet visar hur du animerar värdet för en egenskap som tar en Double med hjälp av nyckelramar.

Exempel

I följande exempel flyttas en rektangel över en skärm. I exemplet används klassen DoubleAnimationUsingKeyFrames för att animera egenskapen X för en TranslateTransform som tillämpas på en Rectangle. Den här animeringen, som upprepas på obestämd tid, använder tre nyckelramar på följande sätt:

  1. Under de första tre sekunderna används en instans av klassen LinearDoubleKeyFrame för att med en stadig hastighet flytta rektangeln längs en bana från startpositionen till position 500. Linjära nyckelramar som LinearDoubleKeyFrame skapa en smidig linjär övergång mellan värden.

  2. I slutet av den fjärde sekunden använder en instans av klassen DiscreteDoubleKeyFrame för att plötsligt flytta rektangeln till nästa position. Diskreta nyckelramar som DiscreteDoubleKeyFrame skapa plötsliga hopp mellan värden. I det här exemplet är rektangeln vid startpositionen och visas plötsligt vid 500-positionen.

  3. Under de sista två sekunderna använder en instans av klassen SplineDoubleKeyFrame för att flytta rektangeln tillbaka till startpositionen. Spline-nyckelramar som SplineDoubleKeyFrame skapar en variabel övergång mellan värden, enligt värdet för egenskapen KeySpline. I det här exemplet börjar rektangeln med att röra sig långsamt och sedan öka exponentiellt mot slutet av tidssegmentet.

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 DoubleAnimationUsingKeyFrames class to
    /// animate the position of an object.
    /// Key frame animations enable you to create complex animations
    /// by specifying multiple destination values
    /// and controlling the animation's interpolation method.
    /// </summary>
    public class AltDoubleAnimationUsingKeyFramesExample : Page
    {
        public AltDoubleAnimationUsingKeyFramesExample()
        {
            Title = "DoubleAnimationUsingKeyFrames 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 a rectangle.
            Rectangle aRectangle = new Rectangle();
            aRectangle.Width = 100;
            aRectangle.Height = 100;
            aRectangle.Stroke = Brushes.Black;
            aRectangle.StrokeThickness = 5;

            // Create a Canvas to contain and
            // position the rectangle.
            Canvas containerCanvas = new Canvas();
            containerCanvas.Width = 610;
            containerCanvas.Height = 300;
            containerCanvas.Children.Add(aRectangle);
            Canvas.SetTop(aRectangle, 100);
            Canvas.SetLeft(aRectangle, 10);

            // Create a TranslateTransform to
            // move the rectangle.
            TranslateTransform animatedTranslateTransform =
                new TranslateTransform();
            aRectangle.RenderTransform = animatedTranslateTransform;

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

            // Create a DoubleAnimationUsingKeyFrames to
            // animate the TranslateTransform.
            DoubleAnimationUsingKeyFrames translationAnimation
                = new DoubleAnimationUsingKeyFrames();
            translationAnimation.Duration = TimeSpan.FromSeconds(6);

            // Animate from the starting position to 500
            // over the first second using linear
            // interpolation.
            translationAnimation.KeyFrames.Add(
                new LinearDoubleKeyFrame(
                    500, // Target value (KeyValue)
                    KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3))) // KeyTime
                );

            // Animate from 500 (the value of the previous key frame)
            // to 400 at 4 seconds using discrete interpolation.
            // Because the interpolation is discrete, the rectangle will appear
            // to "jump" from 500 to 400.
            translationAnimation.KeyFrames.Add(
                new DiscreteDoubleKeyFrame(
                    400, // Target value (KeyValue)
                    KeyTime.FromTimeSpan(TimeSpan.FromSeconds(4))) // KeyTime
                );

            // Animate from 400 (the value of the previous key frame) to 0
            // over two seconds, starting at 4 seconds (the key time of the
            // last key frame) and ending at 6 seconds.
            translationAnimation.KeyFrames.Add(
                new SplineDoubleKeyFrame(
                    0, // Target value (KeyValue)
                    KeyTime.FromTimeSpan(TimeSpan.FromSeconds(6)), // KeyTime
                    new KeySpline(0.6,0.0,0.9,0.0) // KeySpline
                    )
                );

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

            // Set the animation to target the X property
            // of the object named "AnimatedTranslateTransform."
            Storyboard.SetTargetName(translationAnimation, "AnimatedTranslateTransform");
            Storyboard.SetTargetProperty(
                translationAnimation, new PropertyPath(TranslateTransform.XProperty));

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

            // Start the storyboard after the rectangle loads.
            aRectangle.Loaded += delegate(object sender, RoutedEventArgs e)
            {
                translationStoryboard.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 DoubleAnimationUsingKeyFrames class to
    ''' animate the position of an object.
    ''' Key frame animations enable you to create complex animations 
    ''' by specifying multiple destination values
    ''' and controlling the animation's interpolation method.
    ''' </summary>
    Public Class AltDoubleAnimationUsingKeyFramesExample
        Inherits Page
        Public Sub New()
            Title = "DoubleAnimationUsingKeyFrames 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 a rectangle.
            Dim aRectangle As New Rectangle()
            aRectangle.Width = 100
            aRectangle.Height = 100
            aRectangle.Stroke = Brushes.Black
            aRectangle.StrokeThickness = 5

            ' Create a Canvas to contain and
            ' position the rectangle.
            Dim containerCanvas As New Canvas()
            containerCanvas.Width = 610
            containerCanvas.Height = 300
            containerCanvas.Children.Add(aRectangle)
            Canvas.SetTop(aRectangle, 100)
            Canvas.SetLeft(aRectangle, 10)

            ' Create a TranslateTransform to 
            ' move the rectangle.
            Dim animatedTranslateTransform As New TranslateTransform()
            aRectangle.RenderTransform = animatedTranslateTransform

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

            ' Create a DoubleAnimationUsingKeyFrames to
            ' animate the TranslateTransform.
            Dim translationAnimation As New DoubleAnimationUsingKeyFrames()
            translationAnimation.Duration = TimeSpan.FromSeconds(6)

            ' Animate from the starting position to 500
            ' over the first second using linear
            ' interpolation.
            translationAnimation.KeyFrames.Add(New LinearDoubleKeyFrame(500, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3)))) ' KeyTime -  Target value (KeyValue)

            ' Animate from 500 (the value of the previous key frame) 
            ' to 400 at 4 seconds using discrete interpolation.
            ' Because the interpolation is discrete, the rectangle will appear
            ' to "jump" from 500 to 400.
            translationAnimation.KeyFrames.Add(New DiscreteDoubleKeyFrame(400, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(4)))) ' KeyTime -  Target value (KeyValue)

            ' Animate from 400 (the value of the previous key frame) to 0
            ' over two seconds, starting at 4 seconds (the key time of the
            ' last key frame) and ending at 6 seconds.
            translationAnimation.KeyFrames.Add(New SplineDoubleKeyFrame(0, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(6)), New KeySpline(0.6,0.0,0.9,0.0))) ' KeySpline -  KeyTime -  Target value (KeyValue)

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

            ' Set the animation to target the X property
            ' of the object named "AnimatedTranslateTransform."
            Storyboard.SetTargetName(translationAnimation, "AnimatedTranslateTransform")
            Storyboard.SetTargetProperty(translationAnimation, New PropertyPath(TranslateTransform.XProperty))

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

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

            Content = containerCanvas
        End Sub

    End Class
End Namespace

<!-- This example shows how to use the DoubleAnimationUsingKeyFrames to 
     animate the position of an object. 
     Key frame animations enable you to create complex animations 
     by specifying multiple destination values
     and controlling the animation's interpolation method.
-->
<Page 
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="DoubleAnimationUsingKeyFrames Example"
  Background="White" Margin="20">       
  <Canvas Width="610" Height="300">
  
    <!-- The position of this rectangle is animated using 
         a key frame animation. -->
    <Rectangle 
      Canvas.Top="100"
      Canvas.Left="10"
      Height="100"
      Width="100"
      Stroke="Black"
      StrokeThickness="5">
      <Rectangle.RenderTransform>
        <TranslateTransform x:Name="AnimatedTranslateTransform" />
      </Rectangle.RenderTransform>
      
      <Rectangle.Triggers>
        <EventTrigger RoutedEvent="Rectangle.Loaded">
          <BeginStoryboard>
            <Storyboard>

              <!-- Animate the TranslateTransform.X property using 3 KeyFrames
                   which animates the rectangle along a straight line. 
                   This animation repeats indefinitely. -->
              <DoubleAnimationUsingKeyFrames
                Storyboard.TargetName="AnimatedTranslateTransform"
                Storyboard.TargetProperty="X"
                Duration="0:0:6"
                RepeatBehavior="Forever">

                <!-- Using a LinearDoubleKeyFrame, the rectangle moves 
                     steadily from its starting position to 500 over 
                     the first 3 seconds.  -->
                <LinearDoubleKeyFrame Value="500" KeyTime="0:0:3" />

                <!-- Using a DiscreteDoubleKeyFrame, the rectangle suddenly 
                     appears at 400 after the fourth second of the animation. -->
                <DiscreteDoubleKeyFrame Value="400" KeyTime="0:0:4" />

                <!-- Using a SplineDoubleKeyFrame, the rectangle moves 
                     back to its starting point. The
                     animation starts out slowly at first and then speeds up. 
                     This KeyFrame ends after the 6th
                     second. -->
                <SplineDoubleKeyFrame KeySpline="0.6,0.0 0.9,0.00" Value="0" KeyTime="0:0:6" />
              </DoubleAnimationUsingKeyFrames>
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Rectangle.Triggers>
    </Rectangle>
  </Canvas>
</Page>

Det fullständiga exemplet finns i Exempel på keyframe-animering.

För konsekvens med andra animeringsexempel använder kodversionerna av det här exemplet ett Storyboard-objekt för att tillämpa DoubleAnimationUsingKeyFrames. När du använder en enda animering i kod är det också enklare att använda metoden BeginAnimation i stället för att använda en Storyboard. Ett exempel finns i Animera en egenskap utan att använda Storyboard.

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