Get attached property value from content in contentpresenter

Question

I've made a custom window that has a template defined in a resource dictionary. The window has no title bar.

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:dsControls="clr-namespace:Something">
<Style x:Key="WindowRegionStyle"
       TargetType="Window">
    /** Other setters **/
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="ContentControl">
                <Grid>
                    <Border Background="{StaticResource WindowBackground}"
                            BorderBrush="{StaticResource BorderBrushColor}"
                            BorderThickness="1"
                            CornerRadius="8"
                            HorizontalAlignment="Center"
                            VerticalAlignment="Center">
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="Auto" />
                                <ColumnDefinition Width="*" />
                            </Grid.ColumnDefinitions>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="Auto" />
                            </Grid.RowDefinitions>

                            <Border CornerRadius="8,8,0,0"
                                    BorderBrush="{StaticResource BorderBrushColor}"
                                    Background="{StaticResource HeaderColor}"
                                    Grid.ColumnSpan="2"
                                    Grid.Row="0">
                                <Label Content="{Binding Path=(dsControls:WindowDetails.Title), RelativeSource={RelativeSource TemplatedParent}}"
                                       FontSize="20" />
                            </Border>

                            <ContentPresenter Grid.Row="1" Grid.ColumnSpan="2" Content="{TemplateBinding Content}" />

                        </Grid>
                    </Border>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

The content that is added to this template is a UserControl. That all works.

But now I want to define a title in the UserControl. To set the title, I made an attached property 'WindowDetails.Title'.

public static class WindowDetails
{
    public static string GetTitle(DependencyObject obj)
    {
        return (string)obj.GetValue(TitleProperty);
    }

    public static void SetTitle(DependencyObject obj, string value)
    {
        obj.SetValue(TitleProperty, value);
    }

    // Using a DependencyProperty as the backing store for Title.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty TitleProperty =
        DependencyProperty.RegisterAttached("Title", typeof(string), typeof(WindowDetails), new PropertyMetadata(""));

}

And I set the the title in the UserControl like this:

<UserControl x:Class="Something.View"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:dsControls="clr-namespace:Something"
             Width="400"
             dsControls:WindowDetails.Title="Test">

      /** Some content **/
</UserControl>

The problem

I cannot bind the property value to the label in my template.

What I already tried (and went wrong)

<Label Content="{Binding Path=(dsControls:WindowDetails.Title), RelativeSource={RelativeSource TemplatedParent}}"
                                       FontSize="20" />

and

<Label Content="{Binding Path=(dsControls:WindowDetails.Title), RelativeSource={RelativeSource Self}}"
                                       FontSize="20" />

Also, changing the OwnerType of the Attached property:

• To WindowDetails

  public static readonly DependencyProperty TitleProperty = DependencyProperty.RegisterAttached("Title", typeof(string), typeof(WindowDetails), new PropertyMetadata(""));

When I do this, the property is not set. But the content of the label has the default property value.

• To UserControl

  public static readonly DependencyProperty TitleProperty = DependencyProperty.RegisterAttached("Title", typeof(string), typeof(UserControl), new PropertyMetadata(""));

When I do this, the property is set, but the content of the label has no value.

Question

How can I set the attached property in my UserControl and bind it to the content of the label in my template?

Thanks in advance!

Greetings Loetn

Answer 1

This is how you can do this: Give x:Name to your ContentPresenter and refer to it in binding the label.

<Border CornerRadius="8,8,0,0"
   BorderBrush="{StaticResource BorderBrushColor}"
   Background="{StaticResource HeaderColor}"
   Grid.ColumnSpan="2"
   Grid.Row="0">
   <Label Content="{Binding Path=Content.(dsControls:WindowDetails.Title), ElementName="myPresenter"}" FontSize="20" />
</Border>
<ContentPresenter x:Name="myPresenter" Grid.Row="1" Grid.ColumnSpan="2" Content="{TemplateBinding Content}" />

Answer 2

Try using a converter

public class AttchedTitleToTitleConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return (value as FrameworkElement).GetValue(WindowDetails.TitleProperty);
    }

    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}

Add it to your ResourceDictionary:

<local:AttchedTitleToTitleConverter x:Key="titleConverter"/>

And in the binding:

<Label Content="{Binding RelativeSource={RelativeSource Self}, Converter={DynamicResource titleConverter}}"/>

Hope this helps