绑定到动画属性(WPF)

<Grid>
  <Grid.RowDefinitions>
    <RowDefinition Height="*" />
    <RowDefinition Height="Auto" />
  </Grid.RowDefinitions>
  <TextBlock Text="{Binding ElementName=Rect,Path=Width}" Grid.Row="0" />
  <Rectangle Grid.Row="1"
             Name="Rect"
             Height="30"
             Width="50"
             Fill="Blue"
             HorizontalAlignment="Left">
    <Rectangle.Triggers>
      <EventTrigger RoutedEvent="Rectangle.MouseLeftButtonDown">
        <EventTrigger.Actions>
          <BeginStoryboard>
            <Storyboard>
              <DoubleAnimation Storyboard.TargetProperty="Width"
                From="50"
                To="300"
                Duration="0:0:10"/>
            </Storyboard>
          </BeginStoryboard>
        </EventTrigger.Actions>
      </EventTrigger>
    </Rectangle.Triggers>
  </Rectangle>
</Grid>

动画确实会更改值,它会调用传递给DependecProperty.Register的属性更改回调,并且会导致需要布局/渲染过程id。