Timeline.BeginTime Property
Gets or sets the time at which this Timeline should begin. This is a dependency property.
Assembly: PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
'Declaration Public Property BeginTime As Nullable(Of TimeSpan) 'Usage Dim instance As Timeline Dim value As Nullable(Of TimeSpan) value = instance.BeginTime instance.BeginTime = value
<object BeginTime="[-][days.]hours:minutes:seconds[.fractionalSeconds]"/>- or -<object BeginTime="[-][days.]hours:minutes"/>- or - <object BeginTime="[-]days"/>- or -<object BeginTime="{x:Null Markup Extension}"/>
XAML Values
Items in square brackets ([ and ]) are optional.
For the complete TimeSpan syntax, see the Remarks section of the Parse page.
Property Value
Type: System.Nullable(Of TimeSpan)The time at which this Timeline should begin, relative to its parent's BeginTime. If this timeline is a root timeline, the time is relative to its interactive begin time (the moment at which the timeline was triggered). This value may be positive, negative, or Nothing; a Nothing value means the timeline never plays. The default value is zero.
The BeginTime property is useful for creating timelines that play in a sequence: by increasing the BeginTime of successive timelines that share the same parent, you can stagger their play times.
Negative Values
A negative BeginTime value causes a Timeline to behave as though it started at some time in the past. For example, a Timeline with a BeginTime of negative 2.5 seconds and a Duration of 5 seconds will appear to be half-way finished when it starts.
BeginTime and SpeedRatio
The time described by the BeginTime property is measured in the timeline's parent's time. For example, a timeline with a BeginTime of 5 whose parent has a SpeedRatio of 2 actually starts after 2.5 seconds.
A timeline's own SpeedRatio setting does not affect its BeginTime. For example, a timeline with a BeginTime of 5 seconds, a SpeedRatio of 2, and a parent timeline with a SpeedRatio of 1 starts after 5 seconds, not 2.5.
A timeline's BeginTime property determines the beginning of a timeline's active period. If the timeline has a parent timeline, the BeginTime property determines how long it takes the timeline to start after its parent starts. If the timeline is a root timeline (a Storyboard, for example), the BeginTime property determines how long the timeline takes to start playing after it is triggered.
The following example shows several different timelines with different BeginTime settings.
<!-- This example shows how the BeginTime property determines when a timeline starts. Several rectangles are animated by DoubleAnimations with identical durations and target values, but with different BeginTime settings. --> <Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" WindowTitle="BeginTime Example"> <StackPanel Margin="20"> <!-- The rectangles to animate. --> <Rectangle Name="DefaultBeginTimeRectangle" Width="20" Height="20" Fill="Blue" /> <Rectangle Name="DelayedBeginTimeRectangle" Width="20" Height="20" Fill="Blue" /> <Rectangle Name="DelayedAnimationWithDelayedParentRectangle" Width="20" Height="20" Fill="Blue" /> <Rectangle Name="NegativeBeginTimeExampleRectangle" Width="20" Height="20" Fill="Blue" /> <!-- Create a button to start the animations. --> <Button Margin="20" Content="Start Animations"> <Button.Triggers> <EventTrigger RoutedEvent="Button.Click"> <BeginStoryboard> <Storyboard> <!-- This animation starts as soon as the button is clicked, because it has a BeginTime of 0. --> <DoubleAnimation Storyboard.TargetName="DefaultBeginTimeRectangle" Storyboard.TargetProperty="Width" BeginTime="0:0:0" From="100" To="600" Duration="0:0:5" /> <!-- This animation starts 5 seconds after the button is clicked. --> <DoubleAnimation Storyboard.TargetName="DelayedBeginTimeRectangle" Storyboard.TargetProperty="Width" BeginTime="0:0:5" From="100" To="600" Duration="0:0:5" /> <ParallelTimeline BeginTime="0:0:5"> <!-- This animation starts 10 seconds after the button is clicked, because its parent has a BeginTime of 5 seconds and it has a BeginTime of 5 seconds: 5 + 5 = 10. --> <DoubleAnimation Storyboard.TargetName="DelayedAnimationWithDelayedParentRectangle" Storyboard.TargetProperty="Width" BeginTime="0:0:5" From="100" To="600" Duration="0:0:5" /> </ParallelTimeline> <!-- This animation starts as soon as the button is clicked, but it animates from 350 to 600 instead of from 100 to 600 because of its negative BeginTime. The negative BeginTime setting advances the animation, so that it behaves as though it had already been playing for 2.5 seconds as soon as it is started. --> <DoubleAnimation Storyboard.TargetName="NegativeBeginTimeExampleRectangle" Storyboard.TargetProperty="Width" BeginTime="-0:0:2.5" From="100" To="600" Duration="0:0:5" /> </Storyboard> </BeginStoryboard> </EventTrigger> </Button.Triggers> </Button> <!-- This example demonstrates how the BeginTime property works on a root timeline. --> <Rectangle Name="RootTimelineWithDelayedBeginTimeRectangle" Width="20" Height="20" Fill="Blue" > <Rectangle.Triggers> <EventTrigger RoutedEvent="Rectangle.MouseLeftButtonDown"> <BeginStoryboard> <Storyboard BeginTime="0:0:5"> <!-- This animation starts 5 seconds after the left mouse button is pressed, because its parent storyboard (a root timeline) has a BeginTime of 5 seconds. --> <DoubleAnimation Storyboard.TargetName="RootTimelineWithDelayedBeginTimeRectangle" Storyboard.TargetProperty="Width" BeginTime="0:0:0" From="100" To="600" Duration="0:0:2" /> </Storyboard> </BeginStoryboard> </EventTrigger> </Rectangle.Triggers> </Rectangle> </StackPanel> </Page>
More Code
| How to: Simplify Animations by Using Child Timelines | This example shows how to simplify animations by using child ParallelTimeline objects. A Storyboard is a type of Timeline that provides targeting information for the timelines it contains. Use a Storyboard to provide timeline targeting information, including object and property information. |
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.