Can not locate x:Shared in wpf

Please look into this question.

Issue with MVVM view first approach

But 开发者_StackOverflowI'm unable to find "x:Shared" attribute.

here is the msdn link. it works in 3.5 also see below.

From the Book WPF Unleased: Assuming the Conventional x Namespace Prefix. x:Shared --> Attribute on any element in a ResourceDictionary, but only works if XAML is compiled!

//ResourceDictionary
<ResourceDictionary xmlns:x="http://schema.microsoft.con/winfx/2006/xaml>
<Image x:Shared="False" x:Key="zoom" Height="21" Source="zoom.png" />
...