DiscreteSingleKeyFrame Class
System.Windows.Threading::DispatcherObject
System.Windows::DependencyObject
System.Windows::Freezable
System.Windows.Media.Animation::SingleKeyFrame
System.Windows.Media.Animation::DiscreteSingleKeyFrame
Assembly: PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
The DiscreteSingleKeyFrame type exposes the following members.
| Name | Description | |
|---|---|---|
![]() | DiscreteSingleKeyFrame() | Initializes a new instance of the DiscreteSingleKeyFrame class. |
![]() | DiscreteSingleKeyFrame(Single) | Initializes a new instance of the DiscreteSingleKeyFrame class with the specified ending value. |
![]() | DiscreteSingleKeyFrame(Single, KeyTime) | Initializes a new instance of the DiscreteSingleKeyFrame class with the specified ending value and key time. |
| Name | Description | |
|---|---|---|
![]() | CanFreeze | Gets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.) |
![]() | DependencyObjectType | Gets the DependencyObjectType that wraps the CLR type of this instance. (Inherited from DependencyObject.) |
![]() | Dispatcher | Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.) |
![]() | IsFrozen | Gets a value that indicates whether the object is currently modifiable. (Inherited from Freezable.) |
![]() | IsSealed | Gets a value that indicates whether this instance is currently sealed (read-only). (Inherited from DependencyObject.) |
![]() | KeyTime | Gets or sets the time at which the key frame's target Value should be reached. (Inherited from SingleKeyFrame.) |
![]() | Value | Gets or sets the key frame's target value. (Inherited from SingleKeyFrame.) |
| Name | Description | |
|---|---|---|
![]() | CheckAccess | Determines whether the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.) |
![]() | ClearValue(DependencyProperty) | Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.) |
![]() | ClearValue(DependencyPropertyKey) | Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.) |
![]() | Clone | Creates a modifiable clone of the Freezable, making deep copies of the object's values. When copying the object's dependency properties, this method copies expressions (which might no longer resolve) but not animations or their current values. (Inherited from Freezable.) |
![]() | CloneCore | Makes the instance a clone (deep copy) of the specified Freezable using base (non-animated) property values. (Inherited from Freezable.) |
![]() | CloneCurrentValue | Creates a modifiable clone (deep copy) of the Freezable using its current values. (Inherited from Freezable.) |
![]() | CloneCurrentValueCore | Makes the instance a modifiable clone (deep copy) of the specified Freezable using current property values. (Inherited from Freezable.) |
![]() | CoerceValue | Coerces the value of the specified dependency property. This is accomplished by invoking any CoerceValueCallback function specified in property metadata for the dependency property as it exists on the calling DependencyObject. (Inherited from DependencyObject.) |
![]() | CreateInstance | Initializes a new instance of the Freezable class. (Inherited from Freezable.) |
![]() | CreateInstanceCore | Creates a new instance of DiscreteSingleKeyFrame. (Overrides Freezable::CreateInstanceCore().) |
![]() | Equals | Determines whether a provided DependencyObject is equivalent to the current DependencyObject. (Inherited from DependencyObject.) |
![]() | Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
![]() | Freeze() | Makes the current object unmodifiable and sets its IsFrozen property to true. (Inherited from Freezable.) |
![]() | FreezeCore | Makes the Freezable object unmodifiable or tests whether it can be made unmodifiable. (Inherited from Freezable.) |
![]() | GetAsFrozen | Creates a frozen copy of the Freezable, using base (non-animated) property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.) |
![]() | GetAsFrozenCore | Makes the instance a frozen clone of the specified Freezable using base (non-animated) property values. (Inherited from Freezable.) |
![]() | GetCurrentValueAsFrozen | Creates a frozen copy of the Freezable using current property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.) |
![]() | GetCurrentValueAsFrozenCore | Makes the current instance a frozen clone of the specified Freezable. If the object has animated dependency properties, their current animated values are copied. (Inherited from Freezable.) |
![]() | GetHashCode | Gets a hash code for this DependencyObject. (Inherited from DependencyObject.) |
![]() | GetLocalValueEnumerator | Creates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.) |
![]() | GetType | Gets the Type of the current instance. (Inherited from Object.) |
![]() | GetValue | Returns the current effective value of a dependency property on this instance of a DependencyObject. (Inherited from DependencyObject.) |
![]() | InterpolateValue | Returns the interpolated value of a specific key frame at the progress increment provided. (Inherited from SingleKeyFrame.) |
![]() | InterpolateValueCore | Uses discrete interpolation to transition between the previous key frame value and the value of the current key frame. (Overrides SingleKeyFrame::InterpolateValueCore(Single, Double).) |
![]() | InvalidateProperty | Re-evaluates the effective value for the specified dependency property (Inherited from DependencyObject.) |
![]() | MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
![]() | OnChanged | Called when the current Freezable object is modified. (Inherited from Freezable.) |
![]() | OnFreezablePropertyChanged(DependencyObject, DependencyObject) | Ensures that appropriate context pointers are established for a DependencyObjectType data member that has just been set. (Inherited from Freezable.) |
![]() | OnFreezablePropertyChanged(DependencyObject, DependencyObject, DependencyProperty) | This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code. (Inherited from Freezable.) |
![]() | OnPropertyChanged | Overrides the DependencyObject implementation of OnPropertyChanged to also invoke any Changed handlers in response to a changing dependency property of type Freezable. (Inherited from Freezable.) |
![]() | ReadLocalValue | Returns the local value of a dependency property, if it exists. (Inherited from DependencyObject.) |
![]() | ReadPreamble | Ensures that the Freezable is being accessed from a valid thread. Inheritors of Freezable must call this method at the beginning of any API that reads data members that are not dependency properties. (Inherited from Freezable.) |
![]() | SetCurrentValue | Sets the value of a dependency property without changing its value source. (Inherited from DependencyObject.) |
![]() | SetValue(DependencyProperty, Object) | Sets the local value of a dependency property, specified by its dependency property identifier. (Inherited from DependencyObject.) |
![]() | SetValue(DependencyPropertyKey, Object) | Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.) |
![]() | ShouldSerializeProperty | Returns a value that indicates whether serialization processes should serialize the value for the provided dependency property. (Inherited from DependencyObject.) |
![]() | ToString | Returns a string that represents the current object. (Inherited from Object.) |
![]() | VerifyAccess | Enforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.) |
![]() | WritePostscript | Raises the Changed event for the Freezable and invokes its OnChanged method. Classes that derive from Freezable should call this method at the end of any API that modifies class members that are not stored as dependency properties. (Inherited from Freezable.) |
![]() | WritePreamble | Verifies that the Freezable is not frozen and that it is being accessed from a valid threading context. Freezable inheritors should call this method at the beginning of any API that writes to data members that are not dependency properties. (Inherited from Freezable.) |
| Name | Description | |
|---|---|---|
![]() ![]() | IKeyFrame::Value | Gets or sets the value associated with a KeyTime instance. (Inherited from SingleKeyFrame.) |
This class is used as part of a SingleKeyFrameCollection in conjunction with a SingleAnimationUsingKeyFrames to animate a Single property value along a set of key frames.
A key frame defines a segment of the SingleAnimationUsingKeyFrames to which it belongs. Each key frame has a target Value and a KeyTime. The KeyTime specifies the time at which the key frame's Value should be reached. A key frame animates from the target value of the previous key frame to its own target value. It starts when the previous key frame ends and ends when its own key time is reached.
Discrete key frames like DiscreteSingleKeyFrame create sudden "jumps" between values (no Interpolation). In other words, the animated property does not change until the key frame's key time is reached at which point the animated property goes suddenly to the target value.
This example shows how to animate the value of a property that takes a Double by using key frames.
The following 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, which repeats indefinitely, uses three key frames in the following manner:
During the first three seconds, 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.
At the end of the fourth second, 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.
In the final two seconds, 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.
<!-- This example shows how to use the DoubleAnimationUsingKeyFrames to animate the position of an object. Key frame animations enable you to create complex animations by specifying multiple destination values and controlling the animation's interpolation method. --> <Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="DoubleAnimationUsingKeyFrames Example" Background="White" Margin="20"> <Canvas Width="610" Height="300"> <!-- The position of this rectangle is animated using a key frame animation. --> <Rectangle Canvas.Top="100" Canvas.Left="10" Height="100" Width="100" Stroke="Black" StrokeThickness="5"> <Rectangle.RenderTransform> <TranslateTransform x:Name="AnimatedTranslateTransform" /> </Rectangle.RenderTransform> <Rectangle.Triggers> <EventTrigger RoutedEvent="Rectangle.Loaded"> <BeginStoryboard> <Storyboard> <!-- Animate the TranslateTransform.X property using 3 KeyFrames which animates the rectangle along a straight line. This animation repeats indefinitely. --> <DoubleAnimationUsingKeyFrames Storyboard.TargetName="AnimatedTranslateTransform" Storyboard.TargetProperty="X" Duration="0:0:6" RepeatBehavior="Forever"> <!-- 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> </BeginStoryboard> </EventTrigger> </Rectangle.Triggers> </Rectangle> </Canvas> </Page>
For the complete sample, see KeyFrame Animation Sample.
For consistency with other animation examples, the code versions of this example use a Storyboard object to apply the DoubleAnimationUsingKeyFrames. Alternatively, when applying a single animation in code, it is simpler to use the BeginAnimation method instead of using a Storyboard. For an example, see How to: Animate a Property Without Using a Storyboard.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

