#144 – Dependency Property Value Sources: #10 – Inheritance

The tenth source in the list of sources for the base value of a dependency property is inheritance.  A property can get its base value through inheritance if an element higher up in the logical tree sets the property and the property is not overwritten due to a higher precedence rule.

This means that when you set a property value in XAML or in code, that value often “trickles down” the element tree and is applied to other elements that have a property of the same name.

Here’s an example. The value of FontStyle for several controls is inherited from the top-level Window element.

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:m="clr-namespace:PersonLib;assembly=PersonLib"
        Title="MainWindow" Height="350" Width="525" FontStyle="Italic">
    <StackPanel Orientation="Vertical">
        <Button Content="Run" Height="23" Width="75" />
        <Button Content="Skip" Height="23" Width="75" />
        <StackPanel Orientation="Horizontal">
            <Label Content="Inside 2nd StackPanel"/>
            <Label Content="I do my own FontStyle" FontStyle="Normal"/>
        </StackPanel>
    </StackPanel>
</Window>

Here’s what the window looks like: