The document discusses triggers, actions, and behaviors in WPF and Silverlight applications. Triggers define conditions that invoke actions, such as event triggers. Actions are performed in response to triggers and can modify properties or start animations. Behaviors are similar to actions but do not require a trigger and can implement reusable functionality. The document provides examples of timer triggers, custom triggers, and behaviors for fluid layout animations.

1. Triggers, Actions
& Behaviors
Eyal Vardi
CEO E4D Solutions LTD
Microsoft MVP Visual C#
blog: www.eVardi.com

2. Agenda
 Actions
 Triggers
 Behaviors
© 2008 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il

3. Old WPF ( No Silverlight )
<Button Content="Click Me">
<Button.Triggers>
<EventTrigger RoutedEvent="Click">
<EventTrigger.Actions>
<BeginStoryboard Storyboard="{StaticResource sbSpin}"/>
</EventTrigger.Actions>
</EventTrigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsMouseOver" Value="True" />
<Condition Property="Content" Value="{x:Null}" />
</MultiTrigger.Conditions>
<Setter Property="Background" Value="Yellow" />
</MultiTrigger>
</Button.Triggers>
</Button>
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4. .NET 3.5 WPF ( When __, Do __ )
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5. Action Way
<Button Content="Click Me">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<E4D:MyAction TargetName="lbTrace" />
</i:EventTrigger>
</i:Interaction.Triggers>
</Button>
public class MyAction : TargetedTriggerAction<DependencyObject>
{
public MyAction() { ... }
protected override void Invoke(object o) { ... }
}
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6. Perform on
somebody else
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7. Action
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8. Trigger ( When )
 Invokes a bunch of actions at a point when it
decides to do that.
 Event Trigger
 Timer Trigger
 Size Trigger
 The Attach & Detach connect to
the target.
© 2008 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il

9. Timer Trigger Sample
public class TimerTrigger : TriggerBase<DependencyObject>
{
public TimeSpan Interval { get; set; }
protected override void OnAttached()
{
timer = new DispatcherTimer();
timer.Interval = Interval;
timer.Tick += OnTick; timer.Start();
}
void OnTick(object sender, EventArgs e)
{
this.InvokeActions(null);
}
protected override void OnDetaching()
{
timer.Tick -= OnTick; timer = null;
}
DispatcherTimer timer;
}
© 2008 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il

10. Custom Trigger
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11. Behavior
 Behavior don’t need the “When” ( Trigger ),
and don’t have the Invoke.
© 2008 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il

12. Behavior with Command
public class MethodBehavior : Behavior<DependencyObject>
{
public ICommand Command { get; set; }
public MethodBehavior()
{
Command = new ActionCommand( MyMethod );
}
private void MyMethod()
{ <Button Content="Click Me“>
// TODO: <i:Interaction.Behaviors>
} <E4D:MethodBehavior>
} <i:Interaction.Triggers>
<i:KeyTrigger SourceName="...">
<i:InvokeCommandAction CommandName="Command" />
</i:KeyTrigger>
</i:Interaction.Triggers>
</E4D:MethodBehavior>
</i:Interaction.Behaviors>
</Button>
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13. Behaviors
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14. Blend Behaviors
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15. Fluid Move Behavior
 Behavior that watches an element (or a set of
elements) for layout changes, and moves the
element smoothly to the new position when
needed.
<ei:FluidMoveBehavior Duration="00:00:01" AppliesTo="Children">
<ei:FluidMoveBehavior.EaseY>
<BackEase EasingMode="EaseOut" Amplitude="0.5"/>
</ei:FluidMoveBehavior.EaseY>
<ei:FluidMoveBehavior.EaseX>
<BackEase EasingMode="EaseOut" Amplitude="0.5"/>
</ei:FluidMoveBehavior.EaseX>
</ei:FluidMoveBehavior>
© 2008 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il

16. Fluid Move Behavior
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17. Fluid Move Behavior
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18. Fluid Layout in VSM
 Animation between states.
 - Transition Effect
 - Easing Function
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19. Fluid Layout in VSM
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20. Layout States & Transition
 Layout States animate the state changes for
you at the appropriate times, as your items are
added to or removed from the list.
 Edit the ItemContainerStyle and ItemsPanel.
© 2008 E4D LTD. All rights reserved. Tel: 054-5-767-300, Email: Eyal@E4D.co.il

21. Layout States & Transition
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22. FluidMoveTagSetBehavior
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23. Fluid Move Tag Set
Behavior
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