docs-desktop/dotnet-desktop-guide/net/wpf/properties/snippets/how-to-register-an-attached-property/vb/MainWindow.xaml

<Window x:Class="CodeSampleVb.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"/>
	`<Window x:Class="CodeSampleVb.MainWindow"`
	`xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"`
	`xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"/>`