How do I use WPF bindings with RelativeSource?

Question

How do I use RelativeSource with WPF bindings and what are the different use-cases?

Answer 1

Don't forget TemplatedParent:

<Binding RelativeSource="{RelativeSource TemplatedParent}"/>

or

{Binding RelativeSource={RelativeSource TemplatedParent}}

Answer 2

If you want to bind to another property on the object:

{Binding Path=PathToProperty, RelativeSource={RelativeSource Self}}

If you want to get a property on an ancestor:

{Binding Path=PathToProperty, RelativeSource={RelativeSource AncestorType={x:Type typeOfAncestor}}}

If you want to get a property on the templated parent (so you can do 2 way bindings in a ControlTemplate)

{Binding Path=PathToProperty, RelativeSource={RelativeSource TemplatedParent}}

or, shorter (this only works for OneWay bindings):

{TemplateBinding Path=PathToProperty}

Answer 3

Binding RelativeSource={
    RelativeSource Mode=FindAncestor, AncestorType={x:Type ItemType}
}
...

The default attribute of RelativeSource is the Mode property. A complete set of valid values is given here (from MSDN):

• PreviousData Allows you to bind the previous data item (not that control that contains the data item) in the list of data items being displayed.

• TemplatedParent Refers to the element to which the template (in which the data-bound element exists) is applied. This is similar to setting a TemplateBindingExtension and is only applicable if the Binding is within a template.

• Self Refers to the element on which you are setting the binding and allows you to bind one property of that element to another property on the same element.

• FindAncestor Refers to the ancestor in the parent chain of the data-bound element. You can use this to bind to an ancestor of a specific type or its subclasses. This is the mode you use if you want to specify AncestorType and/or AncestorLevel.

Answer 4

Here is the cheat-sheet that does help not being confused: http://www.nbdtech.com/Free/WpfBinding.pdf

-aj

Answer 5

It's worthy of note that for those stumbling across this thinking of Silverlight:

Silverlight offers a reduced subset only, of these commands

Answer 6

I just posted another solution for accessing the DataContext of a parent element in Silverlight that works for me. It uses Binding ElementName.