LinearDoubleKeyFrame LinearDoubleKeyFrame LinearDoubleKeyFrame LinearDoubleKeyFrame Class

Definition

Animates from the Double value of the previous key frame to its own Value using linear interpolation.

public : sealed class LinearDoubleKeyFrame : DoubleKeyFrame, ILinearDoubleKeyFrame
struct winrt::Windows::UI::Xaml::Media::Animation::LinearDoubleKeyFrame : DoubleKeyFrame, ILinearDoubleKeyFrame
public sealed class LinearDoubleKeyFrame : DoubleKeyFrame, ILinearDoubleKeyFrame
Public NotInheritable Class LinearDoubleKeyFrame Inherits DoubleKeyFrame Implements ILinearDoubleKeyFrame
<LinearDoubleKeyFrame .../>
Inheritance
LinearDoubleKeyFrameLinearDoubleKeyFrameLinearDoubleKeyFrameLinearDoubleKeyFrame
Attributes
Windows 10 requirements
Device family
Windows 10 (introduced v10.0.10240.0)
API contract
Windows.Foundation.UniversalApiContract (introduced v1)

Examples

This XAML example moves a rectangle across a screen. The example uses the LinearDoubleKeyFrame class to animate the X property of a TranslateTransform applied to a Rectangle. This animation uses three key frames in the following manner:

  1. During the first three seconds, it uses an instance of the LinearDoubleKeyFrame class to move the rectangle along a path at a steady rate from its starting position to the 500 position. Linear key frames like LinearDoubleKeyFrame create a smooth linear transition between values.
  2. At the end of the fourth second, it uses an instance of the DiscreteDoubleKeyFrame class to suddenly move the rectangle to the next position. Discrete key frames like DiscreteDoubleKeyFrame create sudden jumps between values. In this example, the rectangle is at the starting position and then suddenly appears at the 500 position.
  3. In the final two seconds, it uses an instance of the SplineDoubleKeyFrame class to move the rectangle back to its starting position. Spline key frames like SplineDoubleKeyFrame create a variable transition between values according to the value of the KeySpline property. In this example, the rectangle begins by moving slowly and then speeds up exponentially toward the end of the time segment.
<StackPanel>
    <StackPanel.Resources>
        <Storyboard x:Name="myStoryboard">

            <!-- Animate the TranslateTransform's X property
             from 0 to 350, then 50,
             then 200 over 10 seconds. -->
            <DoubleAnimationUsingKeyFrames
          Storyboard.TargetName="MyAnimatedTranslateTransform"
          Storyboard.TargetProperty="X"
          Duration="0:0:10" EnableDependentAnimation="True">

                <!-- Using a LinearDoubleKeyFrame, the rectangle moves 
                 steadily from its starting position to 500 over 
                 the first 3 seconds.  -->
                <LinearDoubleKeyFrame Value="500" KeyTime="0:0:3" />

                <!-- Using a DiscreteDoubleKeyFrame, the rectangle suddenly 
                 appears at 400 after the fourth second of the animation. -->
                <DiscreteDoubleKeyFrame Value="400" KeyTime="0:0:4" />

                <!-- Using a SplineDoubleKeyFrame, the rectangle moves 
                 back to its starting point. The
                 animation starts out slowly at first and then speeds up. 
                 This KeyFrame ends after the 6th
                 second. -->
                <SplineDoubleKeyFrame KeySpline="0.6,0.0 0.9,0.00" Value="0" KeyTime="0:0:6" />

            </DoubleAnimationUsingKeyFrames>
        </Storyboard>
    </StackPanel.Resources>
    <Rectangle Fill="Blue" Width="50" Height="50" Loaded="Start_Animation">
        <Rectangle.RenderTransform>
            <TranslateTransform x:Name="MyAnimatedTranslateTransform" 
             X="0" Y="0" />
        </Rectangle.RenderTransform>
    </Rectangle>
</StackPanel>
' Start the animation when the object loads
Private Sub Start_Animation(ByVal sender As Object, ByVal e As EventArgs)
    myStoryboard.Begin()
End Sub
// 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 DoubleAnimationUsingKeyFrames with LinearDoubleKeyFrame, otherwise a DoubleAnimation would have been simpler.

For more info on how to use key-frame animations, see Key-frame animations and easing function animations.

Constructors

LinearDoubleKeyFrame() LinearDoubleKeyFrame() LinearDoubleKeyFrame() LinearDoubleKeyFrame()

Initializes a new instance of the LinearDoubleKeyFrame class.

Methods

ClearValue(DependencyProperty) ClearValue(DependencyProperty) ClearValue(DependencyProperty) ClearValue(DependencyProperty)

Clears the local value of a dependency property.

(Inherited from DependencyObject)
GetAnimationBaseValue(DependencyProperty) GetAnimationBaseValue(DependencyProperty) GetAnimationBaseValue(DependencyProperty) 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) GetValue(DependencyProperty) GetValue(DependencyProperty) GetValue(DependencyProperty)

Returns the current effective value of a dependency property from a DependencyObject.

(Inherited from DependencyObject)
ReadLocalValue(DependencyProperty) ReadLocalValue(DependencyProperty) ReadLocalValue(DependencyProperty) ReadLocalValue(DependencyProperty)

Returns the local value of a dependency property, if a local value is set.

(Inherited from DependencyObject)
RegisterPropertyChangedCallback(DependencyProperty,DependencyPropertyChangedCallback) RegisterPropertyChangedCallback(DependencyProperty,DependencyPropertyChangedCallback) RegisterPropertyChangedCallback(DependencyProperty,DependencyPropertyChangedCallback) 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) SetValue(DependencyProperty,Object) SetValue(DependencyProperty,Object) SetValue(DependencyProperty,Object)

Sets the local value of a dependency property on a DependencyObject.

(Inherited from DependencyObject)
UnregisterPropertyChangedCallback(DependencyProperty,Int64) UnregisterPropertyChangedCallback(DependencyProperty,Int64) UnregisterPropertyChangedCallback(DependencyProperty,Int64) UnregisterPropertyChangedCallback(DependencyProperty,Int64)

Cancels a change notification that was previously registered by calling RegisterPropertyChangedCallback.

(Inherited from DependencyObject)

Properties

Dispatcher Dispatcher Dispatcher Dispatcher

Gets the CoreDispatcher that this object is associated with. The CoreDispatcher represents a facility that can access the DependencyObject on the UI thread even if the code is initiated by a non-UI thread.

(Inherited from DependencyObject)
KeyTime KeyTime KeyTime KeyTime

Gets or sets the time at which the key frame's target Value should be reached.

(Inherited from DoubleKeyFrame)
KeyTimeProperty KeyTimeProperty KeyTimeProperty KeyTimeProperty

Identifies the KeyTime dependency property.

(Inherited from DoubleKeyFrame)
Value Value Value Value

Gets or sets the key frame's target value.

(Inherited from DoubleKeyFrame)
ValueProperty ValueProperty ValueProperty ValueProperty

Identifies the Value dependency property.

(Inherited from DoubleKeyFrame)

See Also