DiscreteDoubleKeyFrame class

Applies to Windows and Windows Phone

Animates from the Double value of the previous key frame to its own Value using discrete values.

Inheritance

Object
  DependencyObject
    DoubleKeyFrame
      DiscreteDoubleKeyFrame

Syntax

Public NotInheritable Class DiscreteDoubleKeyFrame
    Inherits DoubleKeyFrame

<DiscreteDoubleKeyFrame .../>

Attributes

[MarshalingBehavior(Agile)]
[Threading(Both)]
[Version(0x06020000)]
[WebHostHidden()]

Members

The DiscreteDoubleKeyFrame class has these types of members:

Constructors

The DiscreteDoubleKeyFrame class has these constructors.

ConstructorDescription
DiscreteDoubleKeyFrame Initializes a new instance of the DiscreteDoubleKeyFrame class.

 

Methods

The DiscreteDoubleKeyFrame class has these methods. It also inherits methods from the Object class.

MethodDescription
ClearValue Clears the local value of a dependency property. (Inherited from DependencyObject)
GetAnimationBaseValue Returns any base value established for a dependency property, which would apply in cases where an animation is not active. (Inherited from DependencyObject)
GetValue Returns the current effective value of a dependency property from a DependencyObject. (Inherited from DependencyObject)
ReadLocalValue Returns the local value of a dependency property, if a local value is set. (Inherited from DependencyObject)
SetValue Sets the local value of a dependency property on a DependencyObject. (Inherited from DependencyObject)

 

Properties

The DiscreteDoubleKeyFrame class has these properties.

PropertyAccess typeDescription

Dispatcher

Read-onlyGets the CoreDispatcher that this object is associated with. (Inherited from DependencyObject)

KeyTime

Read/writeGets or sets the time at which the key frame's target Value should be reached. (Inherited from DoubleKeyFrame)

Value

Read/writeGets or sets the key frame's target value. (Inherited from DoubleKeyFrame)

 

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 can mix discrete, linear, and spline keyframes in the same keyframe collection.

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

Examples

This XAML example moves a rectangle across a screen. The example uses the DoubleAnimationUsingKeyFrames 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.

' Start the animation when the object loads
Private Sub Start_Animation(ByVal sender As Object, ByVal e As EventArgs)
    myStoryboard.Begin()
End Sub


<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>


Requirements

Minimum supported client

Windows 8 [Windows Store apps only]

Minimum supported server

Windows Server 2012 [Windows Store apps only]

Minimum supported phone

Windows Phone 8.1 [Windows Runtime apps only]

Namespace

Windows.UI.Xaml.Media.Animation
Windows::UI::Xaml::Media::Animation [C++]

Metadata

Windows.winmd

See also

Storyboarded animations
Key-frame animations and easing function animations
DoubleKeyFrame
DoubleAnimationUsingKeyFrames
DoubleKeyFrameCollection
KeyTime
Value

 

 

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