Comment : animer une valeur booléenne à l'aide d'images clés
Mise à jour : novembre 2007
Cet exemple montre comment animer la valeur de propriété booléenne d'un contrôle Button à l'aide d'images clés.
Exemple
L'exemple suivant utilise la classe BooleanAnimationUsingKeyFrames pour animer la propriété IsEnabled d'un contrôle Button. Toutes les images clés de cet exemple utilisent une instance de la classe DiscreteBooleanKeyFrame. Les images clés discrètes comme DiscreteBooleanKeyFrame créent des sauts soudains entre les valeurs ; autrement dit, le mouvement de l'animation est saccadé.
// Demonstrates a BooleanAnimationUsingKeyFrames. The animation is used to
// animate the IsEnabled property of a button.
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
{
public class BooleanAnimationUsingKeyFramesExample : Page
{
public BooleanAnimationUsingKeyFramesExample()
{
Title = "BooleanAnimationUsingKeyFrames 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());
StackPanel myStackPanel = new StackPanel();
myStackPanel.Orientation = Orientation.Vertical;
myStackPanel.Margin = new Thickness(20);
// Create a TextBlock to introduce the example.
TextBlock myTextBlock = new TextBlock();
myTextBlock.Text = "Click the button to animate its IsEnabled property"
+ " with aBooleanAnimationUsingKeyFrames animation.";
myStackPanel.Children.Add(myTextBlock);
// Create the Button that is the target of the animation.
Button myButton = new Button();
myButton.Margin = new Thickness(200);
myButton.Content = "Click Me";
myStackPanel.Children.Add(myButton);
// Assign the Button a name so that
// it can be targeted by a Storyboard.
this.RegisterName(
"AnimatedButton", myButton);
// Create a BooleanAnimationUsingKeyFrames to
// animate the IsEnabled property of the Button.
BooleanAnimationUsingKeyFrames booleanAnimation
= new BooleanAnimationUsingKeyFrames();
booleanAnimation.Duration = TimeSpan.FromSeconds(4);
// All the key frames defined below are DiscreteBooleanKeyFrames.
// Discrete key frames create sudden "jumps" between values
// (no interpolation). Only discrete key frames can be used
// for Boolean key frame animations.
// Value at the beginning is false
booleanAnimation.KeyFrames.Add(
new DiscreteBooleanKeyFrame(
false, // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(0.0))) // KeyTime
);
// Value becomes true after the first second.
booleanAnimation.KeyFrames.Add(
new DiscreteBooleanKeyFrame(
true, // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(1.0))) // KeyTime
);
// Value becomes false after the 2nd second.
booleanAnimation.KeyFrames.Add(
new DiscreteBooleanKeyFrame(
false, // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(2.0))) // KeyTime
);
// Value becomes true after the third second.
booleanAnimation.KeyFrames.Add(
new DiscreteBooleanKeyFrame(
true, // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3.0))) // KeyTime
);
// Value becomes false after 3 and half seconds.
booleanAnimation.KeyFrames.Add(
new DiscreteBooleanKeyFrame(
false, // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3.5))) // KeyTime
);
// Value becomes true after the fourth second.
booleanAnimation.KeyFrames.Add(
new DiscreteBooleanKeyFrame(
true, // Target value (KeyValue)
KeyTime.FromTimeSpan(TimeSpan.FromSeconds(4.0))) // KeyTime
);
// Set the animation to target the IsEnabled property
// of the object named "AnimatedButton".
Storyboard.SetTargetName(booleanAnimation, "AnimatedButton");
Storyboard.SetTargetProperty(
booleanAnimation, new PropertyPath(Button.IsEnabledProperty));
// Create a storyboard to apply the animation.
Storyboard myStoryboard = new Storyboard();
myStoryboard.Children.Add(booleanAnimation);
// Start the storyboard when the button is clicked.
myButton.Click += delegate(object sender, RoutedEventArgs e)
{
myStoryboard.Begin(this);
};
Content = myStackPanel;
}
}
}
<!-- Demonstrates a BooleanAnimationUsingKeyFrames. The animation is used to
animate the IsEnabled property of a button. -->
<Page
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
WindowTitle="KeyFrameBoolean Animation Example">
<StackPanel Orientation="Vertical" Margin="20">
<TextBlock>
Click the button to animate its IsEnabled property with a
BooleanAnimationUsingKeyFrames animation.
</TextBlock>
<Button Name="myAnimatedButton" Margin="200">Click Me
<Button.Triggers>
<EventTrigger RoutedEvent="Button.Click">
<BeginStoryboard>
<Storyboard>
<BooleanAnimationUsingKeyFrames
Storyboard.TargetName="myAnimatedButton"
Storyboard.TargetProperty="IsEnabled"
Duration="0:0:4" FillBehavior="HoldEnd">
<!-- All the key frames below are DiscreteBooleanKeyFrames. Discrete key frames create
sudden "jumps" between values (no interpolation). Only discrete key frames can be used
for Boolean key frame animations. -->
<DiscreteBooleanKeyFrame Value="False" KeyTime="0:0:0" />
<DiscreteBooleanKeyFrame Value="True" KeyTime="0:0:1" />
<DiscreteBooleanKeyFrame Value="False" KeyTime="0:0:2" />
<DiscreteBooleanKeyFrame Value="True" KeyTime="0:0:3" />
<DiscreteBooleanKeyFrame Value="False" KeyTime="0:0:3.5" />
<DiscreteBooleanKeyFrame Value="True" KeyTime="0:0:4" />
</BooleanAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
</StackPanel>
</Page>
Pour l'exemple complet, consultez Animation d'image clé, exemple.
Voir aussi
Tâches
Animation d'image clé, exemple
Concepts
Vue d'ensemble des animations d'image clé
Référence
BooleanAnimationUsingKeyFrames