DiscreteInt16KeyFrame Classe

Definição

public ref class DiscreteInt16KeyFrame : System::Windows::Media::Animation::Int16KeyFrame

public class DiscreteInt16KeyFrame : System.Windows.Media.Animation.Int16KeyFrame

type DiscreteInt16KeyFrame = class
    inherit Int16KeyFrame

Public Class DiscreteInt16KeyFrame
Inherits Int16KeyFrame

Herança

Object

DispatcherObject

DependencyObject

Freezable

Int16KeyFrame

DiscreteInt16KeyFrame

Exemplos

A interpolação de uma animação descreve como uma animação transita entre valores ao longo da sua duração. Ao selecionar o tipo de keyframe que usa com a sua animação, pode definir o método de interpolação para esse segmento de keyframe. Existem três tipos diferentes de métodos de interpolação: lineares, discretos e estriados. Este exemplo utiliza a DoubleAnimationUsingKeyFrames para demonstrar estes tipos de interpolação.

O exemplo seguinte utiliza cada um dos diferentes métodos de interpolação disponíveis para a DoubleAnimationUsingKeyFrames classe para animar a posição de um Rectangle.

1. Durante os primeiros três segundos, utiliza uma instância da LinearDoubleKeyFrame classe para mover o retângulo ao longo de um caminho a uma velocidade constante desde a posição inicial até à posição 500. Keyframes lineares como LinearDoubleKeyFrame criam uma transição linear suave entre valores.

2. No final do quarto segundo, usa uma instância da DiscreteDoubleKeyFrame classe para mover subitamente o retângulo para a posição seguinte. Fotogramas-chave discretos como DiscreteDoubleKeyFrame criam saltos súbitos entre valores. Neste exemplo, o retângulo está na posição inicial e depois aparece subitamente na posição 500.

3. Nos dois segundos finais, usa uma instância da SplineDoubleKeyFrame classe para mover o retângulo de volta à sua posição inicial. Os frames-chave spline criam SplineDoubleKeyFrame uma transição variável entre valores de acordo com o valor da KeySpline propriedade. Neste exemplo, o retângulo começa por se mover lentamente e depois acelera exponencialmente no final do segmento temporal

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>

Nem todas <as classes Type>AnimationUsingKeyFrames suportam todos os métodos de interpolação. Para mais informações, consulte a Key-Frame Visão Geral das Animações.

Observações

Esta classe é usada como parte de a Int16KeyFrameCollection em conjunto com a Int16AnimationUsingKeyFrames para animar um Int16 valor de propriedade ao longo de um conjunto de fotogramas-chave.

Um frame chave define um segmento do Int16AnimationUsingKeyFrames ao qual pertence. Cada fotograma-chave tem um alvo Value e um KeyTime. Especifica KeyTime o momento em que os keyframes Value devem ser atingidos. Um fotograma-chave anima do valor-alvo do frame-chave anterior para o seu próprio valor-alvo. Começa quando o fotograma-chave anterior termina e termina quando o seu próprio tempo chave é atingido.

Fotogramas-chave discretas como DiscreteInt16KeyFrame criam "saltos" súbitos entre valores (sem interpolação). Ou seja, a propriedade animada não muda até que o tempo chave do keyframe seja atingido, momento em que a propriedade animada passa subitamente para o valor alvo.

Ver também

• Int16AnimationUsingKeyFrames
• Int16KeyFrameCollection