Timeline.CurrentTimeInvalidated Event

Definition

Namespace:

System.Windows.Media.Animation

Assembly:

PresentationCore.dll

Occurs when the CurrentTime property of the timeline's Clock is updated.

C#

public event EventHandler CurrentTimeInvalidated;

Event Type

EventHandler

Examples

The following example shows how to register for the CurrentTimeInvalidated event.

C#

/*

   This example shows how to register for the
   CurrentTimeInvalidated event
   using a Timeline. 

*/

using System;
using System.Windows;
using System.Windows.Navigation;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Controls;
using System.Windows.Input;

namespace Microsoft.Samples.Animation.TimingBehaviors
{

    public class TimelineCurrentTimeInvalidatedExample : Page {

        private TextBlock currentTimeTextBlock;
        public TimelineCurrentTimeInvalidatedExample()
        {
            
            // Create a name scope.
            NameScope.SetNameScope(this, new NameScope());
            
            WindowTitle = "GetAnimationBaseValue Example";
            StackPanel myPanel = new StackPanel();
            myPanel.Margin = new Thickness(20);     
            
            // Create a rectangle.
            Rectangle animatedRectangle = new Rectangle();
            animatedRectangle.Width = 100;
            animatedRectangle.Height = 50;
            animatedRectangle.Margin = new Thickness(50);
            animatedRectangle.Fill = Brushes.Orange;
            animatedRectangle.Stroke = Brushes.Gray;
            animatedRectangle.StrokeThickness = 2;
            
            // Create a RotateTransform.
            RotateTransform animatedTransform = new RotateTransform();
            animatedTransform.Angle = 0;
            this.RegisterName("animatedTransform", animatedTransform);
            animatedRectangle.RenderTransform = animatedTransform;
            animatedRectangle.RenderTransformOrigin = new Point(0.5,0.5);
            myPanel.Children.Add(animatedRectangle);
            this.Content = myPanel;

            // Create a TextBlock to show the storyboard's current time.
            currentTimeTextBlock = new TextBlock();
            myPanel.Children.Add(currentTimeTextBlock);
            
            // Animate the RotateTransform's angle using a Storyboard.
            DoubleAnimation angleAnimation = new DoubleAnimation(0,360, TimeSpan.FromSeconds(5));
            angleAnimation.RepeatBehavior = RepeatBehavior.Forever;
            Storyboard.SetTargetName(angleAnimation, "animatedTransform");
            Storyboard.SetTargetProperty(angleAnimation, 
                new PropertyPath(RotateTransform.AngleProperty));
  
            Storyboard theStoryboard = new Storyboard();
            theStoryboard.Children.Add(angleAnimation);            
            
            // Register the CurrentTimeInvalidated event.
            // You must register for events before you begin 
            // the storyboard.
            theStoryboard.CurrentTimeInvalidated += 
                new EventHandler(storyboard_CurrentTimeInvalidated);
            
            // Start the storyboard.
            theStoryboard.Begin(animatedRectangle, true);
        }
        
        private void storyboard_CurrentTimeInvalidated(object sender, EventArgs e)
        {

            // Sender is the clock that was created for this storyboard.
            Clock storyboardClock = (Clock)sender;
            
            // Update the TextBlock with the storyboard's current time.
            currentTimeTextBlock.Text = storyboardClock.CurrentTime.ToString();       
        }
    }
}

Remarks

Use the CurrentStateInvalidated event when you want to be notified when the CurrentTime of a timeline's Clock is updated.

The Object parameter of the EventHandler event handler is the timeline's Clock.

Although this event handler appears to be associated with a timeline, it actually registers with the Clock created for this timeline. For more information, see the Timing Events Overview.

Applies to