C# 4 and .NET 4

1020 ❘ ChaPTer 35 cOre wpf
< RowDefinition Height="60" / >
< RowDefinition Height="30" / >
< /Grid.RowDefinitions >
< Image Grid.Row="0" Width="48" Margin="2,2,2,1"
Source="{Binding ImagePath}" / >
< TextBlock Grid.Row="1" FontSize="14"
HorizontalAlignment="Center" Margin="5"
Text="{Binding Name}" / >
< /Grid >
< /DataTemplate >
< /Setter.Value >
< /Setter >
< /Style >
animaTions
With animations you can make a smooth transition using moving elements, color changes, transforms, and
so on. WPF makes it easy to create animations. You can animate the value of any dependency property.
Different animation classes exist to animate the values of different properties, depending on their type.
The major elements of animations are as follows:
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Timeline — Defi nes how a value changes over time. Different kinds of timelines are available for
changing different types of values. The base class for all timelines is Timeline . To animate a double ,
the class DoubleAnimation can be used. Int32Animation is the animation class for int values.
PointAnimation is used to animate points, and ColorAnimation to animate colors.
Storyboard — Used to combine animations. The Storyboard class itself is derived from the base class
TimelineGroup , which derives from Timeline . With DoubleAnimation you can animate a double
value; with Storyboard you combine all the animations that belong together.
Triggers — Start and stop animations. You ’ ve seen property triggers previously. They fi re when a property
value changes. You can also create an event trigger. An event trigger fi res when an event occurs.
The namespace for animation classes is System.Windows.Media.Animation.
Timeline
A Timeline defi nes how a value changes over time. The fi rst example animates the size of an ellipse. Here
a DoubleAnimation timeline changes to a double value. The Triggers property of the Ellipse class is set
to an EventTrigger . The event trigger is fi red when the ellipse is loaded as defi ned with the RoutedEvent
property of the EventTrigger . BeginStoryboard is a trigger action that begins the storyboard. With
the storyboard, a DoubleAnimation element is used to animate the Width property of the Ellipse class.
The animation changes the width of the ellipse from 100 to 300 within three seconds, and reverses the
animation after three seconds. The animation ColorAnimation animates the color from the ellipseBrush
which is used to fi ll the ellipse:
< Ellipse Height="50" Width="100" >
< Ellipse.Fill >
< SolidColorBrush x:Name="ellipseBrush" Color="SteelBlue" / >
< /Ellipse.Fill >
< Ellipse.Triggers >
< EventTrigger RoutedEvent="Ellipse.Loaded" >
< EventTrigger.Actions >
< BeginStoryboard >
< Storyboard Duration="00:00:06" RepeatBehavior="Forever" >
< DoubleAnimation
Storyboard.TargetProperty="(Ellipse.Width)"
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