BeginStoryboard.HandoffBehavior Property

Definition

Namespace:

System.Windows.Media.Animation

Assembly:

PresentationFramework.dll

Gets or sets the proper hand-off behavior to start an animation clock in this storyboard.

C#

public System.Windows.Media.Animation.HandoffBehavior HandoffBehavior { get; set; }

Property Value

HandoffBehavior

One of the HandoffBehavior enumeration values. The default value is SnapshotAndReplace.

Remarks

Using the Compose HandoffBehavior

When you apply a Storyboard, AnimationTimeline, or AnimationClock to a property by using HandoffBehavior.Compose, any Clock objects previously associated with that property continue to consume system resources; the timing system does not remove these clocks automatically.

To avoid performance issues when you apply a large number of clocks using Compose, you should remove composing clocks from the animated property after they complete. There are several ways to remove a clock:

• To remove all clocks from a property, use the ApplyAnimationClock(DependencyProperty, AnimationClock) or BeginAnimation(DependencyProperty, AnimationTimeline) method of the animated object. Specify the property being animated as the first parameter, and null as the second. This will remove all animation clocks from the property.

• To remove a specific AnimationClock from a list of clocks, use the Controller property of the AnimationClock to retrieve a ClockController, then call the Remove method of the ClockController. This is typically done in the Completed event handler for a clock. Note that only root clocks can be controlled by a ClockController; the Controller property of a child clock returns null. Note also that the Completed event is not called if the effective duration of the clock is forever. In that case, the user must determine when to call Remove.

This is primarily an issue for animations on objects that have a long lifetime. When an object is garbage collected, its clocks are also disconnected and garbage collected.

For more information about clock objects, see Animation and Timing System Overview.

Applies to