Posts Tagged ‘Animations’

Kick it like Beckham with WPF Animations

Thursday, February 21st, 2008

I’m just finishing the Animation-Chapter of my German-speaking WPF book (WPF-Buch erscheint im Juni 2008). I had a hard time to find a good idea how to show the reader animations in a really "non-boring", but easy way. And I think I’ve found one.

Animations in WPF are really powerful. You can create them completely in XAML. Even if the example of this post doesn’t make sense for a business application, think of the things you can do with animations:

  • Create buttons with professional hover-effekts
  • Improve the user-interface with some nice effects
  • Ease navigation for the user by animating something he should do now

Of course, Animations in business applications must be placed in the right way. It’s not recommended to animate everything you can. If you do so, your application won’t be serious anymore.

The application we are looking at here isn’t a business application. It’s just a small Loose XAML-File that allows you to become a soccer profi. :-) It show’s how animations are completely created in XAML and how they can be controlled.

Animations in XAML are placed inside Triggers. Either in an EventTriggers Action-Property or in another Triggers EnterAction or ExitAction-Property. These Properties are all of type TriggerAction. The BeginStoryboard-class and some other classes derive from TriggerAction. BeginStoryboard contains a Storyboard. The Storyboard itself contains the Animations.

Below a loose XAML. The Animation (bold) changes the Canvas.Top-Property of an image that contains a ball (the teamgeist-ball of worldcup 2006 Germany). The Animation starts, when a button with the Name btnStart is clicked. Between the ball-image the Canvas contains an image of me. And the clou is, it looks like I kick the ball for thousand times like a real profi.

<Grid Height="260" Width="300">
 <Grid.RowDefinitions>
  <RowDefinition/>
  <RowDefinition Height="Auto"/>
 </Grid.RowDefinitions>
 <Grid.Triggers>
  <EventTrigger RoutedEvent="Button.Click"
    SourceName="btnStart">
   <BeginStoryboard Name="beginStoryboard">
    <Storyboard TargetProperty="(Canvas.Top)" 
      TargetName="imgBall">
     <DoubleAnimation AutoReverse="True" To="110"
     RepeatBehavior="Forever" Duration="0:0:0.25"
     AccelerationRatio="1"/>
    </Storyboard>
   </BeginStoryboard>
  </EventTrigger>
  <EventTrigger RoutedEvent="Button.Click"
    SourceName="btnStop">
   <StopStoryboard BeginStoryboardName="beginStoryboard"/>
  </EventTrigger>
  <EventTrigger RoutedEvent="Button.Click"
    SourceName="btnPause">
   <PauseStoryboard BeginStoryboardName="beginStoryboard"/>
  </EventTrigger>
  <EventTrigger RoutedEvent="Button.Click"
    SourceName="btnResume">
   <ResumeStoryboard BeginStoryboardName="beginStoryboard"/>
  </EventTrigger>
  <EventTrigger RoutedEvent="Button.Click"
    SourceName="btnSpeed2x">
   <SetStoryboardSpeedRatio SpeedRatio="2"
     BeginStoryboardName="beginStoryboard"/>
  </EventTrigger>
  <EventTrigger RoutedEvent="Button.Click"
    SourceName="btnSpeed1x">
   <SetStoryboardSpeedRatio SpeedRatio="1"
     BeginStoryboardName="beginStoryboard"/>
  </EventTrigger>
 </Grid.Triggers>
 <Canvas Width="250" Height="185">
  <Image Height="185" Source="fussballthomi.png"
    Canvas.Left="40"/>
  <Image x:Name="imgBall" Width="25" Canvas.Top="10"
    Canvas.Left="140" Source="teamgeist.png"/>
 </Canvas>
 <DockPanel Grid.Row="1" LastChildFill="False">
  <Button Margin="5" x:Name="btnStart" Content="Start"/>
  <Button Margin="5" x:Name="btnStop" Content="Stop"/>
  <Button Margin="5" x:Name="btnPause" Content="Pause"/>
  <Button Margin="5" x:Name="btnResume" Content="Weiter"/>
  <Button Margin="5" x:Name="btnSpeed1x" Content="1x"/>
  <Button Margin="5" x:Name="btnSpeed2x" Content="2x"/>
 </DockPanel>
</Grid>

Thomas kicks it like beckham. :-)

kickItXAML

More informations about my book, that contains the sample above and hundreds more (also more real world applications), you’ll find by march on www.thomasclaudiushuber.com