Silverlight: Can I put interaction triggers into resources for reuse? - silverlight

Question

I have a bunch of controls using identical interactions triggers across multiple user controls and viewmodels. Is it possible to place these triggers somehow into a resource dictionary for reuse? Here's an example of what a control might look like.
<TextBox x:Name="FirstName" Grid.Row="1" Grid.Column="1">
<i:Interaction.Triggers>
<i:EventTrigger EventName="KeyDown">
<cal:ActionMessage MethodName="KeyPressed" />
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
<TextBox x:Name="Initial" Grid.Row="1" Grid.Column="1">
<i:Interaction.Triggers>
<i:EventTrigger EventName="KeyDown">
<cal:ActionMessage MethodName="KeyPressed" />
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
<TextBox x:Name="LastName" Grid.Row="1" Grid.Column="1">
<i:Interaction.Triggers>
<i:EventTrigger EventName="KeyDown">
<cal:ActionMessage MethodName="KeyPressed" />
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
The cal: namespace is from the Caliburn.Micro MVVM framework and probably isn't relevant to this question.

Answer 1

Its not possible to re-use a single instance of Interaction.Triggers in a resource because it becomes attached a control. That attachment becomes part of its state hence a single instance can't be shared by multiple controls.
You would need to include the Interaction.Triggers in a template so that multiple instances are created. I guess something like the following might work, (warning air code).
<UserControl.Resources>
<DataTemplate x:key="MyTextBox">
<TextBox>
<i:Interaction.Triggers>
<i:EventTrigger EventName="KeyDown">
<cal:ActionMessage MethodName="KeyPressed" />
</i:EventTrigger>
</i:Interaction.Triggers>
</TextBox>
</DataTemplate>
</UserControl.Resources>
...
<ContentPresenter x:Name="FirstName" Grid.Row="1" Grid.Column="1" ContentTemplate="{StaticResource MyTextBox}" />
<ContentPresenter x:Name="Initial" Grid.Row="1" Grid.Column="1" ContentTemplate="{StaticResource MyTextBox}" />
<ContentPresenter x:Name="LastName" Grid.Row="1" Grid.Column="1" ContentTemplate="{StaticResource MyTextBox}" />
It my opinion that this sort of stuff isn't worth it. The Interaction Triggers stuff is really aimed at empowering the designer rather than the developer. A designer isn't that worried that there is some repeatition in the "code".

Answer 2

i have something useful in case you don't have solve completely your issue about reusing Interaction Triggers...
<TextBox x:Name="FirstName" KeyDown="_KeyDown">
...
private void TextBlock_KeyDown(object sender, System.Windows.Input.KeyEventArgs e)
{
Here goes something you wanna reuse for all your TextBox controls..
}
Maybe the better option is to use a design pattern like MVVM and EventToCommand Interactions by GalaSoft