Como animar um duplo usando quadros-chave
Este exemplo mostra como animar o valor de uma propriedade que usa um Double usando quadros-chave.
Exemplo
O exemplo a seguir move um retângulo por uma tela. O exemplo usa a classe para animar a propriedade de um aplicado a DoubleAnimationUsingKeyFramesX um RectangleTranslateTransform arquivo . Essa animação, que se repete indefinidamente, usa três quadros chave da seguinte maneira:
Durante os primeiros três segundos, usa uma instância da LinearDoubleKeyFrame classe para mover o retângulo ao longo de um caminho a uma taxa constante de sua posição inicial para a posição 500. Quadros-chave lineares como LinearDoubleKeyFrame criar uma transição linear suave entre valores.
No final do quarto segundo, usa uma instância da DiscreteDoubleKeyFrame classe para mover repentinamente o retângulo para a próxima posição. Quadros-chave discretos como DiscreteDoubleKeyFrame criar saltos repentinos entre valores. Neste exemplo, o retângulo está na posição inicial e, de repente, aparece na posição 500.
Nos dois segundos finais, usa uma instância da SplineDoubleKeyFrame classe para mover o retângulo de volta à sua posição inicial. Quadros de chave spline como SplineDoubleKeyFrame criar uma transição variável entre valores de acordo com o KeySpline valor da propriedade. Neste exemplo, o retângulo começa a se mover lentamente e acelera exponencialmente em direção ao final do segmento de tempo.
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>
Para ver o exemplo completo, consulte Exemplo de animação de quadro-chave.
Para consistência com outros exemplos de animação, as versões de código deste exemplo usam um Storyboard objeto para aplicar o DoubleAnimationUsingKeyFrames. Como alternativa, ao aplicar uma única animação no código, é mais simples usar o BeginAnimation método em vez de usar um Storyboardarquivo . Para obter um exemplo, consulte Animar uma propriedade sem usar um storyboard.
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