<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" HorizontalAlignment="Center" VerticalAlignment="Center"> <WpfNamespace:Button xmlns:WpfNamespace="http://schemas.microsoft.com/winfx/2006/xaml/presentation" Content="OK"/> </Page>