Como animar uma propriedade usando um Storyboard

Este exemplo mostra como usar um Storyboard para animar propriedades. Para animar uma propriedade usando um Storyboard, crie uma animação para cada propriedade que você deseja animar e também crie um Storyboard para conter as animações.

O tipo de propriedade determina o tipo de animação a ser usada. Por exemplo, para animar uma propriedade que recebe valores Double, utilize um DoubleAnimation. As propriedades TargetName e TargetProperty anexadas especificam o objeto e a propriedade aos quais a animação é aplicada.

Para iniciar um storyboard em Extensible Application Markup Language (XAML), use uma ação BeginStoryboard e um EventTrigger. O EventTrigger inicia a ação BeginStoryboard quando ocorre o evento especificado por sua propriedade RoutedEvent. A ação BeginStoryboard inicia o Storyboard.

O exemplo a seguir usa objetos Storyboard para animar dois controles Button. Para fazer com que o primeiro botão mude de tamanho, a animação é aplicada ao seu Width. Para fazer com que o segundo botão mude de cor, a propriedade Color do SolidColorBrush é usada para definir a Background do botão que é animado.

Exemplo

<!-- StoryboardExample.xaml
     Uses storyboards to animate properties. -->
<Page
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  WindowTitle="Animate Properties with Storyboards">

  <Border Background="White">
    <StackPanel Margin="30" HorizontalAlignment="Left" MinWidth="500">

      <TextBlock>Storyboard Animation Example</TextBlock>
      
      <!-- The width of this button is animated. -->
      <Button Name="myWidthAnimatedButton"
        Height="30" Width="200" HorizontalAlignment="Left">
        A Button   
        <Button.Triggers>
        
          <!-- Animates the width of the first button 
               from 200 to 300. -->         
          <EventTrigger RoutedEvent="Button.Click">
            <BeginStoryboard>
              <Storyboard>           
                <DoubleAnimation Storyboard.TargetName="myWidthAnimatedButton"
                  Storyboard.TargetProperty="Width"
                  From="200" To="300" Duration="0:0:3" />
              </Storyboard>
            </BeginStoryboard>
          </EventTrigger>
        </Button.Triggers>
      </Button>

      <!-- The color of the brush used to paint this button is animated. -->
      <Button Height="30" Width="200" 
        HorizontalAlignment="Left">Another Button
        <Button.Background>
          <SolidColorBrush x:Name="myAnimatedBrush" Color="Blue" />
        </Button.Background>
        <Button.Triggers>
        
        <!-- Animates the color of the brush used to paint 
             the second button from red to blue . -->             
          <EventTrigger RoutedEvent="Button.Click">    
            <BeginStoryboard>
              <Storyboard>
                <ColorAnimation 
                  Storyboard.TargetName="myAnimatedBrush"
                  Storyboard.TargetProperty="Color"
                  From="Red" To="Blue" Duration="0:0:7" />
              </Storyboard>
            </BeginStoryboard>
          </EventTrigger>
        </Button.Triggers>
      </Button>
    </StackPanel>
  </Border>
</Page>

Se usar código, deverá criar um NameScope para um FrameworkElement e registar os nomes dos objetos a serem animados com esse FrameworkElement. Para iniciar as animações no código, use uma ação BeginStoryboard com um EventTrigger. Opcionalmente, você pode usar um manipulador de eventos e o método Begin de Storyboard. O exemplo a seguir mostra como usar o método Begin.

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

namespace Microsoft.Samples.Animation.AnimatingWithStoryboards
{

    // Uses a storyboard to animate the properties
    // of two buttons.
    public class StoryboardExample : Page
    {

        public StoryboardExample()
        {
            // Create a name scope for the page.
            NameScope.SetNameScope(this, new NameScope());

            this.WindowTitle = "Animate Properties using Storyboards";
            StackPanel myStackPanel = new StackPanel();
            myStackPanel.MinWidth = 500;
            myStackPanel.Margin = new Thickness(30);
            myStackPanel.HorizontalAlignment = HorizontalAlignment.Left;
            TextBlock myTextBlock = new TextBlock();
            myTextBlock.Text = "Storyboard Animation Example";
            myStackPanel.Children.Add(myTextBlock);

            //
            // Create and animate the first button.
            //

            // Create a button.
            Button myWidthAnimatedButton = new Button();
            myWidthAnimatedButton.Height = 30;
            myWidthAnimatedButton.Width = 200;
            myWidthAnimatedButton.HorizontalAlignment = HorizontalAlignment.Left;
            myWidthAnimatedButton.Content = "A Button";

            // Set the Name of the button so that it can be referred
            // to in the storyboard that's created later.
            // The ID doesn't have to match the variable name;
            // it can be any unique identifier.
            myWidthAnimatedButton.Name = "myWidthAnimatedButton";

            // Register the name with the page to which the button belongs.
            this.RegisterName(myWidthAnimatedButton.Name, myWidthAnimatedButton);

            // Create a DoubleAnimation to animate the width of the button.
            DoubleAnimation myDoubleAnimation = new DoubleAnimation();
            myDoubleAnimation.From = 200;
            myDoubleAnimation.To = 300;
            myDoubleAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(3000));

            // Configure the animation to target the button's Width property.
            Storyboard.SetTargetName(myDoubleAnimation, myWidthAnimatedButton.Name);
            Storyboard.SetTargetProperty(myDoubleAnimation, new PropertyPath(Button.WidthProperty));

            // Create a storyboard to contain the animation.
            Storyboard myWidthAnimatedButtonStoryboard = new Storyboard();
            myWidthAnimatedButtonStoryboard.Children.Add(myDoubleAnimation);

            // Animate the button width when it's clicked.
            myWidthAnimatedButton.Click += delegate(object sender, RoutedEventArgs args)
                {
                    myWidthAnimatedButtonStoryboard.Begin(myWidthAnimatedButton);
                };

            myStackPanel.Children.Add(myWidthAnimatedButton);

            //
            // Create and animate the second button.
            //

            // Create a second button.
            Button myColorAnimatedButton = new Button();
            myColorAnimatedButton.Height = 30;
            myColorAnimatedButton.Width = 200;
            myColorAnimatedButton.HorizontalAlignment = HorizontalAlignment.Left;
            myColorAnimatedButton.Content = "Another Button";

            // Create a SolidColorBrush to paint the button's background.
            SolidColorBrush myBackgroundBrush = new SolidColorBrush();
            myBackgroundBrush.Color = Colors.Blue;

            // Because a Brush isn't a FrameworkElement, it doesn't
            // have a Name property to set. Instead, you just
            // register a name for the SolidColorBrush with
            // the page where it's used.
            this.RegisterName("myAnimatedBrush", myBackgroundBrush);

            // Use the brush to paint the background of the button.
            myColorAnimatedButton.Background = myBackgroundBrush;

            // Create a ColorAnimation to animate the button's background.
            ColorAnimation myColorAnimation = new ColorAnimation();
            myColorAnimation.From = Colors.Red;
            myColorAnimation.To = Colors.Blue;
            myColorAnimation.Duration = new Duration(TimeSpan.FromMilliseconds(7000));

            // Configure the animation to target the brush's Color property.
            Storyboard.SetTargetName(myColorAnimation, "myAnimatedBrush");
            Storyboard.SetTargetProperty(myColorAnimation, new PropertyPath(SolidColorBrush.ColorProperty));

            // Create a storyboard to contain the animation.
            Storyboard myColorAnimatedButtonStoryboard = new Storyboard();
            myColorAnimatedButtonStoryboard.Children.Add(myColorAnimation);

            // Animate the button background color when it's clicked.
            myColorAnimatedButton.Click += delegate(object sender, RoutedEventArgs args)
                {
                    myColorAnimatedButtonStoryboard.Begin(myColorAnimatedButton);
                };

            myStackPanel.Children.Add(myColorAnimatedButton);
            this.Content = myStackPanel;
        }
    }
}

Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Media.Animation

Namespace SDKSample


    ' Uses a storyboard to animate the properties
    ' of two buttons.
    Public Class StoryboardExample
        Inherits Page
        
        Private Dim WithEvents myWidthAnimatedButton As Button
        Private Dim WithEvents myColorAnimatedButton As Button        
        Private Dim myWidthAnimatedButtonStoryboard As Storyboard
        Private Dim myColorAnimatedButtonStoryboard As Storyboard
        

        Public Sub New()
            ' Create a name scope for the page.
            NameScope.SetNameScope(Me, New NameScope())

            Me.WindowTitle = "Animate Properties using Storyboards"
            Dim myStackPanel As New StackPanel()
            myStackPanel.MinWidth = 500
            myStackPanel.Margin = New Thickness(30)
            myStackPanel.HorizontalAlignment = HorizontalAlignment.Left
            Dim myTextBlock As New TextBlock()
            myTextBlock.Text = "Storyboard Animation Example"
            myStackPanel.Children.Add(myTextBlock)

            '
            ' Create and animate the first button.
            '

            ' Create a button.
            myWidthAnimatedButton = New Button()
            myWidthAnimatedButton.Height = 30
            myWidthAnimatedButton.Width = 200
            myWidthAnimatedButton.HorizontalAlignment = HorizontalAlignment.Left
            myWidthAnimatedButton.Content = "A Button"

            ' Set the Name of the button so that it can be referred
            ' to in the storyboard that's created later.
            ' The ID doesn't have to match the variable name;
            ' it can be any unique identifier.
            myWidthAnimatedButton.Name = "myWidthAnimatedButton"

            ' Register the name with the page to which the button belongs.
            Me.RegisterName(myWidthAnimatedButton.Name, myWidthAnimatedButton)

            ' Create a DoubleAnimation to animate the width of the button.
            Dim myDoubleAnimation As New DoubleAnimation()
            myDoubleAnimation.From = 200
            myDoubleAnimation.To = 300
            myDoubleAnimation.Duration = New Duration(TimeSpan.FromMilliseconds(3000))

            ' Configure the animation to target the button's Width property.
            Storyboard.SetTargetName(myDoubleAnimation, myWidthAnimatedButton.Name)
            Storyboard.SetTargetProperty(myDoubleAnimation, New PropertyPath(Button.WidthProperty))

            ' Create a storyboard to contain the animation.
            myWidthAnimatedButtonStoryboard = New Storyboard()
            myWidthAnimatedButtonStoryboard.Children.Add(myDoubleAnimation)

            myStackPanel.Children.Add(myWidthAnimatedButton)

            '
            ' Create and animate the second button.
            '

            ' Create a second button.
            myColorAnimatedButton = New Button()
            myColorAnimatedButton.Height = 30
            myColorAnimatedButton.Width = 200
            myColorAnimatedButton.HorizontalAlignment = HorizontalAlignment.Left
            myColorAnimatedButton.Content = "Another Button"

            ' Create a SolidColorBrush to paint the button's background.
            Dim myBackgroundBrush As New SolidColorBrush()
            myBackgroundBrush.Color = Colors.Blue

            ' Because a Brush isn't a FrameworkElement, it doesn't
            ' have a Name property to set. Instead, you just
            ' register a name for the SolidColorBrush with
            ' the page where it's used.
            Me.RegisterName("myAnimatedBrush", myBackgroundBrush)

            ' Use the brush to paint the background of the button.
            myColorAnimatedButton.Background = myBackgroundBrush

            ' Create a ColorAnimation to animate the button's background.
            Dim myColorAnimation As New ColorAnimation()
            myColorAnimation.From = Colors.Red
            myColorAnimation.To = Colors.Blue
            myColorAnimation.Duration = New Duration(TimeSpan.FromMilliseconds(7000))

            ' Configure the animation to target the brush's Color property.
            Storyboard.SetTargetName(myColorAnimation, "myAnimatedBrush")
            Storyboard.SetTargetProperty(myColorAnimation, New PropertyPath(SolidColorBrush.ColorProperty))

            ' Create a storyboard to contain the animation.
            myColorAnimatedButtonStoryboard = New Storyboard()
            myColorAnimatedButtonStoryboard.Children.Add(myColorAnimation)

            myStackPanel.Children.Add(myColorAnimatedButton)
            Me.Content = myStackPanel

        End Sub
        
        ' Start the animation when the button is clicked.
        Private Sub myWidthAnimatedButton_Loaded(ByVal sender as object, ByVal args as RoutedEventArgs) Handles myWidthAnimatedButton.Click
        
            myWidthAnimatedButtonStoryboard.Begin(myWidthAnimatedButton)
        
        End Sub        
        
        ' Start the animation when the button is clicked.
        Private Sub myColorAnimatedButton_Loaded(ByVal sender as object, ByVal args as RoutedEventArgs) Handles myColorAnimatedButton.Click
        
            myColorAnimatedButtonStoryboard.Begin(myColorAnimatedButton)
        
        End Sub           
        
    End Class
End Namespace

Para obter mais informações sobre animação e storyboards, consulte Visão geral da animação.

Se utilizares código, não estás limitado a usar objetos Storyboard para animar propriedades. Para obter mais informações e exemplos, consulte Animar uma Propriedade Sem Usar um Storyboard e Animar uma Propriedade Usando um AnimationClock.