Synchronizing control properties with the parent control properties in WPF
Sometimes you need synchronize the properties of a control with the properties of the parent control, in order to accomplish this you can use a binding by element name. In the example below you can see how to make the size of a control equal to its parent control by using binding:
<Canvas>
<DockPanel
Width="{Binding RelativeSource=
{RelativeSource FindAncestor,
AncestorType={x:Type Canvas}},
Path=ActualWidth}"
Height="{Binding RelativeSource=
{RelativeSource FindAncestor,
AncestorType={x:Type Canvas}},
Path=ActualHeight}">
</DockPanel>
</Canvas>