此示例演示如何控制关键帧动画中关键帧的计时。 与其他动画一样，关键帧动画具有 Duration 属性。 除了指定动画的持续时间外，还需要指定该持续时间的哪个部分分配给其每个关键帧。 若要分配时间，请为动画中的每个关键帧指定 KeyTime。
每个关键帧的 KeyTime 指定关键帧结束的时间（它未指定关键帧播放的时间）。 可以将 KeyTime 指定为 TimeSpan 值、百分比或 Uniform 或 Paced 特殊值。
例
以下示例使用 DoubleAnimationUsingKeyFrames 在屏幕上对矩形进行动画处理。 关键帧的关键时间设置为 TimeSpan 值。
/*
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.
'
' Create the a rectangle.
Dim aRectangle As 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.
Dim translateTransform1 As New TranslateTransform()
aRectangle.RenderTransform = translateTransform1
' Create a DoubleAnimationUsingKeyFrames
' to animate the transform.
Dim transformAnimation As 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.
AddHandler aRectangle.Loaded, Sub(sender As Object, e As RoutedEventArgs) 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>
下图展示了每个关键帧的值何时被达到。
下一个示例显示了一个完全相同的动画，但关键帧的关键时间是使用百分比值设置的。
/*
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.
'
' Create the a rectangle.
Dim aRectangle As 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.
Dim translateTransform2 As New TranslateTransform()
aRectangle.RenderTransform = translateTransform2
' Create a DoubleAnimationUsingKeyFrames
' to animate the transform.
Dim transformAnimation As 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.
AddHandler aRectangle.Loaded, Sub(sender As Object, e As RoutedEventArgs) 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>
下图显示了每个关键帧的值何时达到。
下一个示例使用 Uniform 关键时间值。
/*
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.
'
' Create the a rectangle.
Dim aRectangle As 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.
Dim translateTransform3 As New TranslateTransform()
aRectangle.RenderTransform = translateTransform3
' Create a DoubleAnimationUsingKeyFrames
' to animate the transform.
Dim transformAnimation As 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.
AddHandler aRectangle.Loaded, Sub(sender As Object, e As RoutedEventArgs) 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>
下图显示了每个关键帧的值何时达到。
最后一个示例使用 Paced 键时间值。
/*
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.
'
' Create the a rectangle.
Dim aRectangle As 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.
Dim translateTransform4 As New TranslateTransform()
aRectangle.RenderTransform = translateTransform4
' Create a DoubleAnimationUsingKeyFrames
' to animate the transform.
Dim transformAnimation As 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.
AddHandler aRectangle.Loaded, Sub(sender As Object, e As RoutedEventArgs) 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>
以下图例显示了每个关键帧何时达到了其特定值。
为简单起见，此示例的代码版本使用本地动画，而不是情节提要，因为只将单个动画应用于单个属性，但可以修改示例以改用情节提要。 有关如何在代码中声明动画板的示例，请参阅 使用动画板为属性添加动画。
有关完整示例，请参阅 关键帧动画示例。 有关关键帧动画的详细信息，请参阅 Key-Frame 动画概述。
