Avalonia/src/Perspex.Diagnostics/DevTools.paml

<UserControl xmlns="https://github.com/perspex">
  <Grid RowDefinitions="Auto,*,Auto">
    <TabStrip SelectedIndex="{Binding SelectedTab, Mode=TwoWay}">
      <TabStripItem Content="Logical Tree"/>
      <TabStripItem Content="Visual Tree"/>
    </TabStrip>

    <ContentControl Content="{Binding Content}" Grid.Row="1"/> 
    
    <StackPanel Gap="4" Orientation="Horizontal" Grid.Row="2">
      <TextBlock>Hold Ctrl+Shift over a control to inspect.</TextBlock>
      <Separator Width="8"/>
      <TextBlock>Focused:</TextBlock>
      <TextBlock Text="{Binding FocusedControl}"/>
      <Separator Width="8"/>
      <TextBlock>Pointer Over:</TextBlock>
      <TextBlock Text="{Binding PointerOverElement}"/>
    </StackPanel>
  </Grid>
</UserControl>