Export (0) Print
Expand All
This topic has not yet been rated - Rate this topic

LinearThicknessKeyFrame Class

Animates from the Thickness value of the previous key frame to its own Value using linear interpolation.

Namespace:  System.Windows.Media.Animation
Assembly:  PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
public class LinearThicknessKeyFrame : ThicknessKeyFrame
<LinearThicknessKeyFrame .../>

This class is used as part of a ThicknessKeyFrameCollection in conjunction with a ThicknessAnimationUsingKeyFrames to animate a Thickness property value along a set of key frames.

A key frame defines a segment of the ThicknessAnimationUsingKeyFrames 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.

Linear key frames like LinearThicknessKeyFrame create a smooth, linear interpolation between values.

This example shows how to animate the BorderThickness property of a Border.

The following example uses the ThicknessAnimationUsingKeyFrames class to animate the BorderThickness property of a Border. This animation uses three key frames in the following manner:

  1. During the first half second, uses an instance of the LinearThicknessKeyFrame class to gradually increase the thickness of the border. The example uses LinearThicknessKeyFrame to create a smooth linear increase between values.

  2. At the end of the next half second, uses an instance of the DiscreteThicknessKeyFrame class to suddenly increase the thickness of the border. Discrete key frames like those derived from DiscreteThicknessKeyFrame create sudden jumps between values, that is, the movement of the animation is jerky.

  3. During the final two seconds, uses an instance of the SplineThicknessKeyFrame class to decrease the thickness of the border. Spline key frames like those derived from SplineThicknessKeyFrame create a variable transition between values according to the values of the KeySpline property. In this key frame, the animation starts off slow and speeds up exponentially toward the end of the time segment.

<!-- This example shows how to use the ThicknessAnimationUsingKeyFrames to create
an animation on the BorderThickness property of a Border. -->
<Page  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  x:Class="Microsoft.Samples.KeyFrameExamples.ThicknessAnimationUsingKeyFramesExample"
  Name="myRootElement"
  WindowTitle="ThicknessAnimationUsingKeyFrames Example">

  <StackPanel Orientation="Vertical" HorizontalAlignment="Center">
    <Border Background="#99FFFFFF" BorderBrush="#CCCCFF" BorderThickness="1"
    Margin="0,60,0,20" Padding="20"  >
      <Border.Triggers>
        <EventTrigger RoutedEvent="Border.Loaded">
          <BeginStoryboard>
            <Storyboard>

              <!-- Animating the BorderThickness property uses 3 KeyFrames. -->
              <ThicknessAnimationUsingKeyFrames
                Storyboard.TargetProperty="BorderThickness"
                Duration="0:0:5" FillBehavior="HoldEnd" RepeatBehavior="Forever">
                <ThicknessAnimationUsingKeyFrames.KeyFrames>

                  <!-- Using a LinearThicknessKeyFrame, thickness increases gradually
                  over the first half second of the animation. -->
                  <LinearThicknessKeyFrame KeyTime="0:0:0.5">
                    <LinearThicknessKeyFrame.Value>
                      <Thickness Left="8" Right="8" Top="6" Bottom="6" />
                    </LinearThicknessKeyFrame.Value>
                  </LinearThicknessKeyFrame>

                  <!-- Using a DiscreteThicknessKeyFrame, thickness increases suddenly
                  after the first second of the animation. -->
                  <DiscreteThicknessKeyFrame KeyTime="0:0:1">
                    <DiscreteThicknessKeyFrame.Value>
                      <Thickness Left="28" Right="28" Top="24" Bottom="24" />
                    </DiscreteThicknessKeyFrame.Value>
                  </DiscreteThicknessKeyFrame>

                  <!-- Using a SplineThicknessKeyFrame, thickness decreases slowly at first
                  and then suddenly contracts. This KeyFrame takes 2 seconds. -->
                  <SplineThicknessKeyFrame KeySpline="0.6,0.0 0.9,0.00" KeyTime="0:0:3">
                    <SplineThicknessKeyFrame.Value>
                      <Thickness Left="1" Right="1" Top="1" Bottom="8" />
                    </SplineThicknessKeyFrame.Value>
                  </SplineThicknessKeyFrame>

                </ThicknessAnimationUsingKeyFrames.KeyFrames>
              </ThicknessAnimationUsingKeyFrames>
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger>
      </Border.Triggers>

      <TextBlock>
        This example shows how to use the ThicknessAnimationUsingKeyFrames to create
        an animation on the BorderThickness property of a Border. 
      </TextBlock>
    </Border>

  </StackPanel>
</Page>

For the complete sample, see KeyFrame Animation Sample.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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.

.NET Framework

Supported in: 3.5, 3.0
Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2014 Microsoft. All rights reserved.