Skip to content

Latest commit

 

History

History
44 lines (33 loc) · 4.15 KB

how-to-animate-a-double-by-using-key-frames.md

File metadata and controls

44 lines (33 loc) · 4.15 KB
Raw
title description ms.date dev_langs helpviewer_keywords ms.assetid
How to: Animate a Double by Using Key Frames
Learn how to use the DoubleAnimationUsingKeyFrames class to animate the value of a property that takes a Double by using key frames.
03/30/2017
csharp
vb
Doubles [WPF], animating with key frames
animation [WPF], Doubles with key frames
key frames [WPF], animating Doubles with
3a1a7dba-7694-4907-8a2f-3408baebfa82

How to: Animate a Double by Using Key Frames

This example shows how to animate the value of a property that takes a xref:System.Double by using key frames.

Example

The following example moves a rectangle across a screen. The example uses the xref:System.Windows.Media.Animation.DoubleAnimationUsingKeyFrames class to animate the xref:System.Windows.Media.TranslateTransform.X%2A property of a xref:System.Windows.Media.TranslateTransform applied to a xref:System.Windows.Shapes.Rectangle. This animation, which repeats indefinitely, uses three key frames in the following manner:

  1. During the first three seconds, uses an instance of the xref:System.Windows.Media.Animation.LinearDoubleKeyFrame class to move the rectangle along a path at a steady rate from its starting position to the 500 position. Linear key frames like xref:System.Windows.Media.Animation.LinearDoubleKeyFrame create a smooth linear transition between values.

  2. At the end of the fourth second, uses an instance of the xref:System.Windows.Media.Animation.DiscreteDoubleKeyFrame class to suddenly move the rectangle to the next position. Discrete key frames like xref:System.Windows.Media.Animation.DiscreteDoubleKeyFrame create sudden jumps between values. In this example, the rectangle is at the starting position and then suddenly appears at the 500 position.

  3. In the final two seconds, uses an instance of the xref:System.Windows.Media.Animation.SplineDoubleKeyFrame class to move the rectangle back to its starting position. Spline key frames like xref:System.Windows.Media.Animation.SplineDoubleKeyFrame create a variable transition between values according to the value of the xref:System.Windows.Media.Animation.SplineDoubleKeyFrame.KeySpline%2A property. In this example, the rectangle begins by moving slowly and then speeds up exponentially toward the end of the time segment.

[!code-csharpkeyframes_snip#AltDoubleAnimationUsingKeyFramesWholePage] [!code-vbkeyframes_snip#AltDoubleAnimationUsingKeyFramesWholePage] [!code-xamlkeyframes_snip#AltDoubleAnimationUsingKeyFramesWholePage]

For the complete sample, see KeyFrame Animation Sample.

For consistency with other animation examples, the code versions of this example use a xref:System.Windows.Media.Animation.Storyboard object to apply the xref:System.Windows.Media.Animation.DoubleAnimationUsingKeyFrames. Alternatively, when applying a single animation in code, it is simpler to use the xref:System.Windows.Media.Animation.Animatable.BeginAnimation%2A method instead of using a xref:System.Windows.Media.Animation.Storyboard. For an example, see Animate a Property Without Using a Storyboard.

See also

  • xref:System.Windows.Media.Animation.DoubleAnimationUsingKeyFrames
  • xref:System.Windows.Shapes.Rectangle
  • xref:System.Windows.Media.Animation.LinearDoubleKeyFrame
  • xref:System.Windows.Media.Animation.DiscreteDoubleKeyFrame
  • xref:System.Windows.Media.Animation.SplineDoubleKeyFrame
  • Key-Frame Animations Overview
  • Key-Frame How-to Topics