How to apply DependencyProperty values to child user controls? - wpf

Question

I have multiple instances of the same custom user control in a StackPanel. Each instance needs the same DependencyProperty "ControlWidth". Instead of setting each user control with the same property, I want to set it only once in the parent StackPanel
<StackPanel>
<propwin:PropertyEditControl Label="First" ControlWidth="180" />
<propwin:PropertyEditControl Label="First" ControlWidth="180" />
...
</StackPanel>
I used to do this with Style properties
<StackPanel>
<StackPanel.Resources>
<Style TargetType="{x:Type propwin:PropertyEditControl}">
<Setter Property="ControlWidth" Value="180" />
</Style>
</StackPanel.Resources>
<propwin:PropertyEditControl Label="First" />
<propwin:PropertyEditControl Label="Second" />
...
</StackPanel>
Update:
Thanks to Anatoliy, who mention that my code (the one I showed here) should work. I now tracked down the problem. Inside my PropertyEditControl.xaml I define a validation style:
<UserControl x:Class="MyModule.PropertyEditControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:MyModule">
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/MyModule;component/UI/ResourceDictionaries/ResourceLibrary.xaml" />
</ResourceDictionary.MergedDictionaries>
<Style TargetType="local:PropertyEditControl">
<Setter Property="Validation.ErrorTemplate" Value="{StaticResource ValidationErrorTemplate}" />
</Style>
<Style x:Key="PropertyNameStyle" TargetType="DockPanel">
<Setter Property="Width" Value="{Binding ControlWidth}" />
<Setter Property="DockPanel.Dock" Value="Left" />
</Style>
...
If I remove the <Style TargetType="local:PropertyEditControl"> style it works!

Answer 1

It turned out that my original approach should have worked. The reason why it hasn't was a misplaced Style Resource inside the user control. Anyway, the correct answer to my initial question is: To set a DependencyProperty value for multiple controls only once, you have to set it inside the container style definition:
<StackPanel>
<StackPanel.Resources>
<Style TargetType="{x:Type propwin:PropertyEditControl}">
<Setter Property="ControlWidth" Value="180" />
</Style>
</StackPanel.Resources>
<propwin:PropertyEditControl Label="First" />
<propwin:PropertyEditControl Label="Second" />
...
</StackPanel>