Vista - Why setting triggers on a ControlTemplate works but not on a style?

Hi

I need to understand when I should put triggers in the style and when I
should put them in a ControlTemplate. I lost a couple of hours before I
tried to move my logic from the Style.Triggers to a ControlTemplate.Triggers

Please explain when I should use Style.Triggers and when it's useless to
do so. Thanks

Here is the result of my experiment.

<Style x:Key="POListItemStyle2" TargetType="{x:Type ListViewItem}">

<Setter Property="Foreground" Value="Red"/>
<!-- The following is commented because it doesn't work, you have to
implement the logic in a template property
<Style.Triggers>
<Trigger Property="IsSelected" Value="true">
<Setter Property="Background" Value="Blue"/>
<Setter Property="BorderBrush" Value="Yellow" />
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsSelected" Value="true" />
<Condition Property="Selector.IsSelectionActive"
Value="false" />
</MultiTrigger.Conditions>
<Setter Property="Background" Value="Blue"/>
<Setter Property="BorderBrush" Value="Yellow" />
</MultiTrigger>
</Style.Triggers>-->
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ListViewItem}">
<Border Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Padding="{TemplateBinding Padding}">
<StackPanel>
<GridViewRowPresenter/>
</StackPanel>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsSelected" Value="true">
<Trigger.Setters>
<Setter Property="Background" Value="Yellow"/>
</Trigger.Setters>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

Any help in understanding the difference in the code above would be
appreciated.

Thanks

Phil

Although I cannot explain this behavior... I did hit it in the past...
and do remember that I used DataTriggers instead of triggers... and it
worked from there...

I do not see this behavior anymore.... But I have no idea why...

I hope that this "temp" fix can help you...

Philippe Lavoie wrote:
> Hi
>
> I need to understand when I should put triggers in the style and when I
> should put them in a ControlTemplate. I lost a couple of hours before I
> tried to move my logic from the Style.Triggers to a ControlTemplate.Triggers
>
> Please explain when I should use Style.Triggers and when it's useless to
> do so. Thanks
>
> Here is the result of my experiment.
>
> <Style x:Key="POListItemStyle2" TargetType="{x:Type ListViewItem}">
>
> <Setter Property="Foreground" Value="Red"/>
> <!-- The following is commented because it doesn't work, you have to
> implement the logic in a template property
> <Style.Triggers>
> <Trigger Property="IsSelected" Value="true">
> <Setter Property="Background" Value="Blue"/>
> <Setter Property="BorderBrush" Value="Yellow" />
> </Trigger>
> <MultiTrigger>
> <MultiTrigger.Conditions>
> <Condition Property="IsSelected" Value="true" />
> <Condition Property="Selector.IsSelectionActive"
> Value="false" />
> </MultiTrigger.Conditions>
> <Setter Property="Background" Value="Blue"/>
> <Setter Property="BorderBrush" Value="Yellow" />
> </MultiTrigger>
> </Style.Triggers>-->
> <Setter Property="Template">
> <Setter.Value>
> <ControlTemplate TargetType="{x:Type ListViewItem}">
> <Border Background="{TemplateBinding Background}"
> BorderBrush="{TemplateBinding BorderBrush}"
> BorderThickness="{TemplateBinding BorderThickness}"
> Padding="{TemplateBinding Padding}">
> <StackPanel>
> <GridViewRowPresenter/>
> </StackPanel>
> </Border>
> <ControlTemplate.Triggers>
> <Trigger Property="IsSelected" Value="true">
> <Trigger.Setters>
> <Setter Property="Background" Value="Yellow"/>
> </Trigger.Setters>
> </Trigger>
> </ControlTemplate.Triggers>
> </ControlTemplate>
> </Setter.Value>
> </Setter>
> </Style>
>
> Any help in understanding the difference in the code above would be
> appreciated.
>
> Thanks
>
> Phil

I though DataTrigger didn't work with events. Anyway, I would have like
to know the actual story, i.e. a bug inside WPF or there is a concept
that I'm not quite grasping yet...

Phil

Marcus wrote:
> Although I cannot explain this behavior... I did hit it in the past...
> and do remember that I used DataTriggers instead of triggers... and it
> worked from there...
>
> I do not see this behavior anymore.... But I have no idea why...
>
> I hope that this "temp" fix can help you...
>
> Philippe Lavoie wrote:
>
>>Hi
>>
>>I need to understand when I should put triggers in the style and when I
>>should put them in a ControlTemplate. I lost a couple of hours before I
>>tried to move my logic from the Style.Triggers to a ControlTemplate.Triggers
>>
>>Please explain when I should use Style.Triggers and when it's useless to
>>do so. Thanks
>>
>>Here is the result of my experiment.
>>
>><Style x:Key="POListItemStyle2" TargetType="{x:Type ListViewItem}">
>>
>> <Setter Property="Foreground" Value="Red"/>
>> <!-- The following is commented because it doesn't work, you have to
>>implement the logic in a template property
>><Style.Triggers>
>> <Trigger Property="IsSelected" Value="true">
>> <Setter Property="Background" Value="Blue"/>
>> <Setter Property="BorderBrush" Value="Yellow" />
>> </Trigger>
>> <MultiTrigger>
>> <MultiTrigger.Conditions>
>> <Condition Property="IsSelected" Value="true" />
>> <Condition Property="Selector.IsSelectionActive"
>> Value="false" />
>> </MultiTrigger.Conditions>
>> <Setter Property="Background" Value="Blue"/>
>> <Setter Property="BorderBrush" Value="Yellow" />
>> </MultiTrigger>
>> </Style.Triggers>-->
>> <Setter Property="Template">
>> <Setter.Value>
>> <ControlTemplate TargetType="{x:Type ListViewItem}">
>> <Border Background="{TemplateBinding Background}"
>> BorderBrush="{TemplateBinding BorderBrush}"
>> BorderThickness="{TemplateBinding BorderThickness}"
>> Padding="{TemplateBinding Padding}">
>> <StackPanel>
>> <GridViewRowPresenter/>
>> </StackPanel>
>> </Border>
>> <ControlTemplate.Triggers>
>> <Trigger Property="IsSelected" Value="true">
>> <Trigger.Setters>
>> <Setter Property="Background" Value="Yellow"/>
>> </Trigger.Setters>
>> </Trigger>
>> </ControlTemplate.Triggers>
>> </ControlTemplate>
>> </Setter.Value>
>> </Setter>
>> </Style>
>>
>>Any help in understanding the difference in the code above would be
>>appreciated.
>>
>>Thanks
>>
>>Phil
>
>