Question

In <Window.Resources> I have defined following style:

    <Style x:Key='textBlockStyle' TargetType='TextBlock'>         <Setter Property='Margin' Value='5,0,5,0'/>     </Style> 

I have defined some grid where I have four TextBlocks:

    <WrapPanel>         <TextBlock Style='{StaticResource textBlockStyle}'>Server</TextBlock>         <TextBlock Style='{StaticResource textBlockStyle}'>IP</TextBlock>         <TextBlock Style='{StaticResource textBlockStyle}'>Port</TextBlock>         <TextBlock Style='{StaticResource textBlockStyle}'>Status</TextBlock>     </WrapPanel> 

Problem: I need to reference the textBlockStyle four times.

Question: Is it possible to set that style just once at in WrapPanel or somewhere else without repeating the reference to the style?

Maybe something like:

    <WrapPanel Style='{StaticResource textBlockStyle}'>         <TextBlock>Server</TextBlock>         <TextBlock>IP</TextBlock>         <TextBlock>Port</TextBlock>         <TextBlock>Status</TextBlock>     </WrapPanel> 

I am not searching for a global solution! I could delete that x:Key='textBlockStyle' property, but that would affect all TextBlocks in the Window. I need a more selective mechanism, but without that ugly code duplication.

Answer 1

You have several options, presented here in order of how well they scale.

Option 1: Define the Style without a key at a lower level

You can stick the resource at the WrapPanel level so that it only affects controls inside that WrapPanel:

<WrapPanel>     <WrapPanel.Resources>         <Style TargetType='TextBlock'>             <Setter Property='Margin' Value='5,0,5,0'/>         </Style>     </WrapPanel.Resources>      <!-- TextBlocks here --> </WrapPanel> 

Notice the lack of key. This Style will apply to all TextBlocks within the WrapPanel.

Option 2: Define the Style with a key and again without at a lower level

If you define the Style at a higher level with a key, you can then define another Style at a lower level without a key, and base that Style on the higher level one:

<Window>     <Window.Resources>         <Style TargetType='TextBlock' x:Key='textBlockStyle'>             <Setter Property='Margin' Value='5,0,5,0'/>         </Style>     </Window.Resources>      <WrapPanel>         <WrapPanel.Resources>             <Style TargetType='TextBlock' BasedOn='{StaticResource textBlockStyle'/>         </WrapPanel.Resources>          <!-- TextBlocks here -->     </WrapPanel> </Window> 

This results in a Style being automatically applied to TextBlocks inside the WrapPanel, but not outside it. Also, you don’t duplicate the details of the Style – they are stored at a higher level.

Option 3: Place the Styles in a ResourceDictionary and selectively merge it

Finally, you can place your Styles in a separate ResourceDictionary and selectively merge that dictionary into a control’s Resources collection:

<!-- TextBlockStyles.xaml --> <ResourceDictionary>     <Style TargetType='TextBlock'>         <Setter Property='Margin' Value='5,0,5,0'/>     </Style> </ResourceDictionary>  <!-- Window.xaml --> <Window>     <WrapPanel>         <WrapPanel.Resources>             <ResourceDictionary>                 <ResourceDictionary.MergedDictionaries>                     <ResourceDictionary Source='TextBlockStyles.xaml'/>                 </ResourceDictionary.MergedDictionaries>             </ResourceDictionary>         </WrapPanel.Resources>     </WrapPanel> </Window>  <!-- Alternative Window.xaml if you have only one RD to merge in --> <Window>     <WrapPanel>         <WrapPanel.Resources>             <ResourceDictionary Source='TextBlockStyles.xaml'/>         </WrapPanel.Resources>     </WrapPanel> </Window> 

Now you can have as many style sets defined in separate dictionaries as you like, and then selectively apply them to your element tree.