ClockState Enumeration
Describes the potential states of a timeline's Clock object.
Assembly: PresentationCore (in PresentationCore.dll)
| Member name | Description | |
|---|---|---|
| Active | The current Clock time changes in direct relation to that of its parent. If the timeline is an animation, it is actively affecting targeted properties, so their value may change from tick (a sampling point in time) to tick. If the timeline has children, they may be Active, Filling, or Stopped. | |
| Filling | The Clock timing continues, but does not change in relation to that of its parent. If the timeline is an animation, it is actively affecting targeted properties, but its values don't change from tick to tick. If the timeline has children, they may be Active, Filling, or Stopped. | |
| Stopped | The Clock timing is halted, making the clock's current time and progress values undefined. If this timeline is an animation, it no longer affects targeted properties. If this timeline has children, they are also Stopped. |
Note that ClockState does not indicate whether a clock is paused or the direction in which time is flowing.
These explanations rely on the concept of ticks; for a detailed explanation see the Animation and Timing System Overview.
A clock's CurrentStateInvalidated event occurs when its CurrentState becomes invalid, such as when the clock starts or stops. You can register for this event with directly using a Clock, or you can register using a Timeline.
In the following example, a Storyboard and two DoubleAnimation objects are used to animate the width of two rectangles. The CurrentStateInvalidated event is used to listen for clock state changes.
<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="Microsoft.Samples.Animation.TimingBehaviors.StateExample" Background="LightGray"> <StackPanel Margin="20"> <TextBlock Name="ParentTimelineStateTextBlock"></TextBlock> <TextBlock Name="Animation1StateTextBlock"></TextBlock> <Rectangle Name="Rectangle01" Width="100" Height="50" Fill="Orange" /> <TextBlock Name="Animation2StateTextBlock"></TextBlock> <Rectangle Name="Rectangle02" Width="100" Height="50" Fill="Gray" /> <Button Content="Start Animations" Margin="20"> <Button.Triggers> <EventTrigger RoutedEvent="Button.Click"> <BeginStoryboard> <Storyboard RepeatBehavior="2x" AutoReverse="True" CurrentStateInvalidated="parentTimelineStateInvalidated" > <DoubleAnimation Storyboard.TargetName="Rectangle01" Storyboard.TargetProperty="Width" From="10" To="200" Duration="0:0:9" BeginTime="0:0:1" CurrentStateInvalidated="animation1StateInvalidated"/> <DoubleAnimation Storyboard.TargetName="Rectangle02" Storyboard.TargetProperty="Width" From="10" To="200" Duration="0:0:8" BeginTime="0:0:1" CurrentStateInvalidated="animation2StateInvalidated" /> </Storyboard> </BeginStoryboard> </EventTrigger> </Button.Triggers> </Button> </StackPanel> </Page>
The following illustration shows the different states the animations enter as the parent timeline (Storyboard) progresses.

The following table shows the times at which Animation1's CurrentStateInvalidated event fires:
Time (Seconds) | 1 | 10 | 19 | 21 | 30 | 39 |
State | Active | Active | Stopped | Active | Active | Stopped |
The following table shows the times at which Animation2's CurrentStateInvalidated event fires:
Time (Seconds) | 1 | 9 | 11 | 19 | 21 | 29 | 31 | 39 |
State | Active | Filling | Active | Stopped | Active | Filling | Active | Stopped |
Notice that Animation1's CurrentStateInvalidated event fires at 10 seconds, even though its state remains Active. That's because its state changed at 10 seconds, but it changed from Active to Filling and then back to Active in the same tick.
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.