Avalonia/samples/Sandbox/MainWindow.axaml

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
        xmlns:sandbox="clr-namespace:Sandbox"
        x:DataType="sandbox:MainViewModel"
        x:Class="Sandbox.MainWindow">
  <Window.DataContext>
    <sandbox:MainViewModel />
  </Window.DataContext>
  <StackPanel>

    <ComboBox MinWidth="100" ItemsSource="{Binding Items}" SelectedItem="{Binding SelectedItem}"/>
    <!--<Button Content="Set Property1 manually" Command="{Binding ButtonClick}"/>-->

    <!--<TextBlock Text="TextBlock bound to the ComboBox SelectedItem" Margin="0,10,0,0"/>-->
    <TextBlock Foreground="Black" TextAlignment="Right" Background="LightBlue" Margin="1" Text="{Binding SelectedItem, StringFormat='({0})'}"/>

    <!--<TextBlock Margin="0,10,0,0" TextWrapping="Wrap" Foreground="WhiteSmoke">
      TextBlock bound to the Property1 which get set: <LineBreak/>
      -> To the <Span Foreground="Blue">value</Span> in the SelectedItem property Setter <LineBreak/>
      -> To a string on ButtonClick
    </TextBlock>
    <TextBlock Foreground="Black" TextAlignment="Right" Background="LightBlue" Margin="1" Text="{Binding Property1, StringFormat='({0})'}"/>

    <TextBlock TextAlignment="Right" Background="LightBlue" Margin="1" Foreground="Black">
      SelectedItem = <Run Text="{Binding SelectedItem}" />
      Property1 = <Run Text="{Binding Property1}" />
    </TextBlock>-->

  </StackPanel>
</Window>