Avalonia/samples/MobileSandbox/MainWindow.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:local="clr-namespace:MobileSandbox"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        CanResize="False"
        Width="720" Height="1280"
        Title="Mobile Sandbox"
        Icon="/Assets/test_icon.ico"
        WindowStartupLocation="CenterScreen"
        x:Class="MobileSandbox.MainWindow">
  <local:MainView />
</Window>