Question

I have created a custom control but I can’t bind a property to the content like this :

<Style TargetType="control:Pie">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="control:Pie">
                    <Border
                        Background="{TemplateBinding Background}"
                        BorderBrush="{TemplateBinding BorderBrush}"
                        BorderThickness="{TemplateBinding BorderThickness}">

                        <ContentControl Content="{Binding Path=Test}"/>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

And in my control

public string Test
    {
        get { return (string)GetValue(TestProperty); }
        set { SetValue(TestProperty, value); }
    }
    public static readonly DependencyProperty TestProperty =
        DependencyProperty.Register(
            "Test",
            typeof(string),
            typeof(Pie),
            new PropertyMetadata(null));

When I create the control a set a string in the Test property but nothing appears in the view…

Answer 1

TemplateBinding is used to bind to the templated control and therefore only works in ControlTemplate. Just 2 Lines above you already used TemplateBinding for Background, BorderBrush and BorderThickness.

Binding on the otherhand binds to the DataContext, which is an object used to take “business” related data from the user. It should be independant of how your controls works and

As a rule of thumb: If you use a normal binding in a ControlTemplate, which doesn’t have a RelativeSource, ElementName or Source set, it usually should not appear in a ControlTemplate or Style.