Cómo: Controlar la temporización de animaciones y fotogramas clave
Actualización: noviembre 2007
En este ejemplo se muestra cómo controlar la temporización de fotogramas clave dentro de una animación de fotogramas clave. Como sucede con las demás animaciones, las animaciones de fotogramas clave tienen una propiedad Duration. Además de especificar la duración de la animación, necesita especificar qué parte de esa duración se asigna a cada uno de sus fotogramas clave. Para la asignación del tiempo, debe especificar KeyTime para cada fotograma clave de la animación.
El elemento KeyTime de cada fotograma clave especifica cuándo finaliza (no el tiempo durante el cual se reproduce). Puede especificar KeyTime como un valor TimeSpan, como un porcentaje o como el valor especial Uniform o Paced.
Ejemplo
En el ejemplo siguiente se utiliza DoubleAnimationUsingKeyFrames para animar un rectángulo por la pantalla. Los tiempos clave de los fotogramas clave se establecen con valores TimeSpan.
/*
This Rectangle is animated with KeyTimes using TimeSpan Values.
It moves horizontally to 100 in the first 3 seconds, 100 to 300 in
the next second, and 300 to 500 in the last 6 seconds.
*/
// Create the a rectangle.
Rectangle aRectangle = new Rectangle();
aRectangle.Fill = Brushes.Blue;
aRectangle.Stroke = Brushes.Black;
aRectangle.StrokeThickness = 5;
aRectangle.Width = 50;
aRectangle.Height = 50;
// Create a transform to move the rectangle
// across the screen.
TranslateTransform translateTransform1 =
new TranslateTransform();
aRectangle.RenderTransform = translateTransform1;
// Create a DoubleAnimationUsingKeyFrames
// to animate the transform.
DoubleAnimationUsingKeyFrames transformAnimation =
new DoubleAnimationUsingKeyFrames();
transformAnimation.Duration = TimeSpan.FromSeconds(10);
// Animate to 100 at 3 seconds.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(100, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(3))));
// Animate to 300 at 4 seconds.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(300, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(4))));
// Animate to 500 at 10 seconds.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(500, KeyTime.FromTimeSpan(TimeSpan.FromSeconds(10))));
// Start the animation when the rectangle is loaded.
aRectangle.Loaded += delegate(object sender, RoutedEventArgs e)
{
translateTransform1.BeginAnimation(TranslateTransform.XProperty, transformAnimation);
};
<!-- This Rectangle is animated with KeyTimes using TimeSpan Values.
It moves horizontally to 100 in the first 3 seconds, 100 to 300 in
the next second, and 300 to 500 in the last 6 seconds. -->
<Rectangle Fill="Blue" Stroke="Black" StrokeThickness="5"
Width="50" Height="50">
<Rectangle.RenderTransform>
<TranslateTransform x:Name="TranslateTransform1" />
</Rectangle.RenderTransform>
<Rectangle.Triggers>
<EventTrigger RoutedEvent="Rectangle.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="TranslateTransform1"
Storyboard.TargetProperty="X"
Duration="0:0:10">
<!-- These KeyTime properties are specified as TimeSpan values
which are in the form of "hours:minutes:seconds". -->
<LinearDoubleKeyFrame Value="100" KeyTime="0:0:3" />
<LinearDoubleKeyFrame Value="300" KeyTime="0:0:4" />
<LinearDoubleKeyFrame Value="500" KeyTime="0:0:10" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Rectangle.Triggers>
</Rectangle>
La ilustración siguiente muestra cuándo se alcanza el valor de cada fotograma clave.
.png "Los valores de clave se alcanzan a 3, 4 y 10 segundos")
En el ejemplo siguiente se muestra una animación que es idéntica; la única diferencia es que los tiempos clave de los fotogramas clave se establecen con valores de porcentaje.
/*
This rectangle moves horizontally to 100 in the first 3 seconds,
100 to 300 in the next second, and 300 to 500 in the last 6 seconds.
*/
// Create the a rectangle.
Rectangle aRectangle = new Rectangle();
aRectangle.Fill = Brushes.Purple;
aRectangle.Stroke = Brushes.Black;
aRectangle.StrokeThickness = 5;
aRectangle.Width = 50;
aRectangle.Height = 50;
// Create a transform to move the rectangle
// across the screen.
TranslateTransform translateTransform2 =
new TranslateTransform();
aRectangle.RenderTransform = translateTransform2;
// Create a DoubleAnimationUsingKeyFrames
// to animate the transform.
DoubleAnimationUsingKeyFrames transformAnimation =
new DoubleAnimationUsingKeyFrames();
transformAnimation.Duration = TimeSpan.FromSeconds(10);
// Animate to 100 at 30% of the animation's duration.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(100, KeyTime.FromPercent(0.3)));
// Animate to 300 at 40% of the animation's duration.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(300, KeyTime.FromPercent(0.4)));
// Animate to 500 at 100% of the animation's duration.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(500, KeyTime.FromPercent(1.0)));
// Start the animation when the rectangle is loaded.
aRectangle.Loaded += delegate(object sender, RoutedEventArgs e)
{
translateTransform2.BeginAnimation(TranslateTransform.XProperty, transformAnimation);
};
<!-- This rectangle moves horizontally to 100 in the first 3 seconds,
100 to 300 in the next second, and 300 to 500 in the last 6 seconds.-->
<Rectangle Fill="Purple" Stroke="Black" StrokeThickness="5"
Width="50" Height="50">
<Rectangle.RenderTransform>
<TranslateTransform x:Name="TranslateTransform2" />
</Rectangle.RenderTransform>
<Rectangle.Triggers>
<EventTrigger RoutedEvent="Rectangle.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="TranslateTransform2"
Storyboard.TargetProperty="X"
Duration="0:0:10">
<!-- KeyTime properties are expressed as Percentages. -->
<LinearDoubleKeyFrame Value="100" KeyTime="30%" />
<LinearDoubleKeyFrame Value="300" KeyTime="40%" />
<LinearDoubleKeyFrame Value="500" KeyTime="100%" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Rectangle.Triggers>
</Rectangle>
La ilustración siguiente muestra cuándo se alcanza el valor de cada fotograma clave.
.png "Los valores de clave se alcanzan a 3, 4 y 10 segundos")
En el ejemplo siguiente se utilizan valores de tiempos clave Uniform.
/*
This rectangle is animated with KeyTimes using Uniform values.
Goes to 100 in the first 3.3 seconds, 100 to
300 in the next 3.3 seconds, 300 to 500 in the last 3.3 seconds.
*/
// Create the a rectangle.
Rectangle aRectangle = new Rectangle();
aRectangle.Fill = Brushes.Red;
aRectangle.Stroke = Brushes.Black;
aRectangle.StrokeThickness = 5;
aRectangle.Width = 50;
aRectangle.Height = 50;
// Create a transform to move the rectangle
// across the screen.
TranslateTransform translateTransform3 =
new TranslateTransform();
aRectangle.RenderTransform = translateTransform3;
// Create a DoubleAnimationUsingKeyFrames
// to animate the transform.
DoubleAnimationUsingKeyFrames transformAnimation =
new DoubleAnimationUsingKeyFrames();
transformAnimation.Duration = TimeSpan.FromSeconds(10);
/*
KeyTime properties are expressed with values of Uniform. When a key time is set to
"Uniform" the total allotted time of the animation is divided evenly between key frames.
In this example, the total duration of the animation is ten seconds and there are four
key frames each of which are set to "Uniform", therefore, the duration of each key frame
is 3.3 seconds (10/3).
*/
// Animate to 100.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(100, KeyTime.Uniform));
// Animate to 300.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(300, KeyTime.Uniform));
// Animate to 500.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(500, KeyTime.Uniform));
// Start the animation when the rectangle is loaded.
aRectangle.Loaded += delegate(object sender, RoutedEventArgs e)
{
translateTransform3.BeginAnimation(TranslateTransform.XProperty, transformAnimation);
};
<!-- This rectangle is animated with KeyTimes using Uniform values.
Goes to 100 in the first 3.3 seconds, 100 to
300 in the next 3.3 seconds, 300 to 500 in the last 3.3 seconds. -->
<Rectangle Fill="Red" Stroke="Black" StrokeThickness="5"
Width="50" Height="50">
<Rectangle.RenderTransform>
<TranslateTransform x:Name="TranslateTransform3" />
</Rectangle.RenderTransform>
<Rectangle.Triggers>
<EventTrigger RoutedEvent="Rectangle.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="TranslateTransform3"
Storyboard.TargetProperty="X"
Duration="0:0:10">
<!-- KeyTime properties are expressed with values of Uniform. When a key time is set to
"Uniform" the total allotted time of the animation is divided evenly between key frames.
In this example, the total duration of the animation is ten seconds and there are four
key frames each of which are set to "Uniform", therefore, the duration of each key frame
is 3.3 seconds (10/3). -->
<LinearDoubleKeyFrame Value="100" KeyTime="Uniform" />
<LinearDoubleKeyFrame Value="300" KeyTime="Uniform" />
<LinearDoubleKeyFrame Value="500" KeyTime="Uniform" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Rectangle.Triggers>
</Rectangle>
La ilustración siguiente muestra cuándo se alcanza el valor de cada fotograma clave.
.png "Los valores de clave se alcanzan a 3.3, 6.6 y 9.9 segundos")
En el último ejemplo se utilizan valores de tiempos clave Paced.
/*
This rectangle is animated with KeyTimes using Paced Values.
The rectangle moves between key frames at uniform rate except for first key frame
because using a Paced value on the first KeyFrame in a collection of frames gives a time of zero.
*/
// Create the a rectangle.
Rectangle aRectangle = new Rectangle();
aRectangle.Fill = Brushes.Orange;
aRectangle.Stroke = Brushes.Black;
aRectangle.StrokeThickness = 5;
aRectangle.Width = 50;
aRectangle.Height = 50;
// Create a transform to move the rectangle
// across the screen.
TranslateTransform translateTransform4 =
new TranslateTransform();
aRectangle.RenderTransform = translateTransform4;
// Create a DoubleAnimationUsingKeyFrames
// to animate the transform.
DoubleAnimationUsingKeyFrames transformAnimation =
new DoubleAnimationUsingKeyFrames();
transformAnimation.Duration = TimeSpan.FromSeconds(10);
/*
Use Paced values when a constant rate is desired.
The time allocated to a key frame with a KeyTime of "Paced" is
determined by the time allocated to the other key frames of the animation. This time is
calculated to attempt to give a "paced" or "constant velocity" for the animation.
*/
// Animate to 100.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(100, KeyTime.Paced));
// Animate to 300.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(300, KeyTime.Paced));
// Animate to 500.
transformAnimation.KeyFrames.Add(
new LinearDoubleKeyFrame(500, KeyTime.Paced));
// Start the animation when the rectangle is loaded.
aRectangle.Loaded += delegate(object sender, RoutedEventArgs e)
{
translateTransform4.BeginAnimation(TranslateTransform.XProperty, transformAnimation);
};
<!-- This rectangle is animated with KeyTimes using Paced Values.
The rectangle moves between key frames at uniform rate except for first key frame
because using a Paced value on the first KeyFrame in a collection of frames gives a time of zero. -->
<Rectangle Fill="Orange" Stroke="Black" StrokeThickness="5"
Width="50" Height="50">
<Rectangle.RenderTransform>
<TranslateTransform x:Name="TranslateTransform4" />
</Rectangle.RenderTransform>
<Rectangle.Triggers>
<EventTrigger RoutedEvent="Rectangle.Loaded">
<BeginStoryboard>
<Storyboard>
<DoubleAnimationUsingKeyFrames
Storyboard.TargetName="TranslateTransform4"
Storyboard.TargetProperty="X"
Duration="0:0:10">
<!-- Use Paced values when a constant rate is desired.
The time allocated to a key frame with a KeyTime of "Paced" is
determined by the time allocated to the other key frames of the animation. This time is
calculated to attempt to give a "paced" or "constant velocity" for the animation. -->
<LinearDoubleKeyFrame Value="100" KeyTime="Paced" />
<LinearDoubleKeyFrame Value="300" KeyTime="Paced" />
<LinearDoubleKeyFrame Value="500" KeyTime="Paced" />
</DoubleAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Rectangle.Triggers>
</Rectangle>
La ilustración siguiente muestra cuándo se alcanza el valor de cada fotograma clave.
.png "Los valores de clave se alcanzan a 0, 5 y 10 segundos")
Para que no fueran tan complejas, las versiones de código de este ejemplo usan animaciones locales, no guiones gráficos, porque sólo se aplica una animación a una propiedad. Sin embargo, los ejemplos se pueden modificar para utilizar guiones gráficos. Para obtener un ejemplo donde se muestra cómo declarar un guión gráfico en el código, vea Cómo: Animar una propiedad utilizando un guión gráfico.
Para obtener el ejemplo completo, vea Ejemplo KeyFrame Animation. Para obtener más información sobre las animaciones de fotogramas clave, vea Información general sobre animaciones de fotogramas clave.
Vea también
Conceptos
Información general sobre animaciones de fotogramas clave
Información general sobre animaciones