Avalonia/samples/ControlCatalog/App.xaml

<Application xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:vm="using:ControlCatalog.ViewModels"
             x:DataType="vm:ApplicationViewModel"
             x:CompileBindings="True"
             Name="Avalonia ControlCatalog"
             x:Class="ControlCatalog.App">
  <Application.Styles>
    <Style Selector="TextBlock.h1, TextBlock.h2, TextBlock.h3">
      <Setter Property="TextWrapping" Value="Wrap" />
    </Style>
    <Style Selector="TextBlock.h1">
      <Setter Property="FontSize" Value="16" />
      <Setter Property="FontWeight" Value="Medium" />
    </Style>
    <Style Selector="TextBlock.h2">
      <Setter Property="FontSize" Value="14" />
    </Style>
    <Style Selector="TextBlock.h3">
      <Setter Property="FontSize" Value="12" />
    </Style>
    <Style Selector="Label.h1">
      <Setter Property="FontSize" Value="16" />
      <Setter Property="FontWeight" Value="Medium" />
    </Style>
    <Style Selector="Label.h2">
      <Setter Property="FontSize" Value="14" />
    </Style>
    <Style Selector="Label.h3">
      <Setter Property="FontSize" Value="12" />
    </Style>
    <StyleInclude Source="avares://ControlSamples/HamburgerMenu/HamburgerMenu.xaml" />
  </Application.Styles>
  <TrayIcon.Icons>
    <TrayIcons>
      <TrayIcon Icon="/Assets/test_icon.ico" ToolTipText="Avalonia Tray Icon ToolTip">
        <TrayIcon.Menu>
          <NativeMenu>
            <NativeMenuItem Header="Settings">
              <NativeMenu>
                <NativeMenuItem Header="Option 1" ToggleType="Radio" IsChecked="True" Command="{Binding ToggleCommand}" />
                <NativeMenuItem Header="Option 2" ToggleType="Radio" IsChecked="True" Command="{Binding ToggleCommand}" />
                <NativeMenuItemSeparator />
                <NativeMenuItem Header="Option 3" ToggleType="CheckBox" IsChecked="True" Command="{Binding ToggleCommand}" />
                <NativeMenuItem Icon="/Assets/test_icon.ico" Header="Restore Defaults" Command="{Binding ToggleCommand}" />
              </NativeMenu>
            </NativeMenuItem>
            <NativeMenuItem Header="Exit" Command="{Binding ExitCommand}" />
          </NativeMenu>
        </TrayIcon.Menu>
      </TrayIcon>
    </TrayIcons>
  </TrayIcon.Icons>
</Application>