Avalonia/samples/XamlTestApplication/Views/MainWindow.xaml

<Window x:Class="XamlTestApplication.MainWindow"
        xmlns="https://github.com/perspex"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
        Title="Perspex Test Application" Height="350" Width="525">
    <Window.Styles>
        <Style>
            
        </Style>
    </Window.Styles>
</Window>