LinearPointKeyFrame Class
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
public ref class LinearPointKeyFrame sealed : PointKeyFrame/// [Windows.Foundation.Metadata.Activatable(65536, "Microsoft.UI.Xaml.WinUIContract")]
/// [Windows.Foundation.Metadata.ContractVersion(Microsoft.UI.Xaml.WinUIContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
class LinearPointKeyFrame final : PointKeyFrame[Windows.Foundation.Metadata.Activatable(65536, "Microsoft.UI.Xaml.WinUIContract")]
[Windows.Foundation.Metadata.ContractVersion(typeof(Microsoft.UI.Xaml.WinUIContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Threading(Windows.Foundation.Metadata.ThreadingModel.Both)]
public sealed class LinearPointKeyFrame : PointKeyFramePublic NotInheritable Class LinearPointKeyFrame
Inherits PointKeyFrame<LinearPointKeyFrame .../>
- Inheritance
- Attributes
Examples
This XAML example moves an ellipse along a triangular path. The example uses the PointAnimationUsingKeyFrames class to animate the Center property of an EllipseGeometry. This animation uses three key frames in the following manner:
- During the first half second, it uses an instance of the LinearPointKeyFrame class to move the ellipse along a path at a steady rate from its starting position. Linear key frames such as LinearPointKeyFrame create a smooth linear interpolation between values.
- During the end of the next half second, it uses an instance of the DiscretePointKeyFrame class to suddenly move the ellipse along the path to the next position. Discrete key frames like DiscretePointKeyFrame create sudden jumps between values.
- During the final two seconds, it uses an instance of the SplinePointKeyFrame class to move the ellipse back to its starting position. Spline key frames like SplinePointKeyFrame create a variable transition between values according to the values of the KeySpline property. In this example, the animation begins slowly and speeds up exponentially toward the end of the time segment.
<Canvas Width="400" Height="300">
<Canvas.Resources>
<Storyboard x:Name="myStoryboard">
<!-- Animating the Center property uses 3 KeyFrames, which animate
the ellipse allong a triangular path. -->
<PointAnimationUsingKeyFrames
Storyboard.TargetProperty="Center"
Storyboard.TargetName="MyAnimatedEllipseGeometry"
Duration="0:0:5" RepeatBehavior="Forever" EnableDependentAnimation="True">
<!-- Over the first half second, Using a LinearPointKeyFrame, the ellipse
moves steadily from its starting position along the first line of the
trianglar path. -->
<LinearPointKeyFrame KeyTime="0:0:0.5" Value="100,300" />
<!-- Using a DiscretePointKeyFrame, the ellipse suddenly changes position
after the first second of the animation. -->
<DiscretePointKeyFrame KeyTime="0:0:1" Value="400,300" />
<!-- Using a SplinePointKeyFrame, the ellipse moves back to its starting
position. It moves slowly at first and then speeds up. This key frame
takes 2 seconds to complete. -->
<SplinePointKeyFrame KeySpline="0.6,0.0 0.9,0.00"
KeyTime="0:0:3" Value="200,100" />
</PointAnimationUsingKeyFrames>
</Storyboard>
</Canvas.Resources>
<Path Fill="Blue" Loaded="Start_Animation">
<Path.Data>
<!-- Describes an ellipse. -->
<EllipseGeometry x:Name="MyAnimatedEllipseGeometry"
Center="200,100" RadiusX="15" RadiusY="15" />
</Path.Data>
</Path>
</Canvas>
// Start the animation when the object loads
private void Start_Animation(object sender, RoutedEventArgs e)
{
myStoryboard.Begin();
}
Remarks
Key-frame animations permit more than one target value that is reached at a point along the animation timeline. In other words each key frame can specify a different intermediate value, and the last key frame reached is the final animation value. By specifying multiple values to animate, you can make more complex animations. You'd typically have at least two keyframes in a PointAnimationUsingKeyFrames with LinearPointKeyFrame, otherwise a PointAnimation would have been simpler.
For more info on how to use key-frame animations, see Key-frame animations and easing function animations.
Constructors
| LinearPointKeyFrame() |
Initializes a new instance of the LinearPointKeyFrame class. |
Properties
| Dispatcher |
Always returns |
| DispatcherQueue |
Gets the |
| KeyTime |
Gets or sets the time at which the key frame's target Value should be reached. (Inherited from PointKeyFrame) |
| Value |
Gets or sets the key frame's target value. (Inherited from PointKeyFrame) |
Methods
| ClearValue(DependencyProperty) |
Clears the local value of a dependency property. (Inherited from DependencyObject) |
| GetAnimationBaseValue(DependencyProperty) |
Returns any base value established for a dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject) |
| GetValue(DependencyProperty) |
Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject) |
| ReadLocalValue(DependencyProperty) |
Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject) |
| RegisterPropertyChangedCallback(DependencyProperty, DependencyPropertyChangedCallback) |
Registers a notification function for listening to changes to a specific DependencyProperty on this DependencyObject instance. (Inherited from DependencyObject) |
| SetValue(DependencyProperty, Object) |
Sets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject) |
| UnregisterPropertyChangedCallback(DependencyProperty, Int64) |
Cancels a change notification that was previously registered by calling RegisterPropertyChangedCallback. (Inherited from DependencyObject) |