Avalonia/samples/ControlCatalog/Pages/TextBoxPage.xaml

<UserControl xmlns="https://github.com/perspex">
  <StackPanel Orientation="Vertical" Gap="4">
    <TextBlock Classes="h1">TextBox</TextBlock>
    <TextBlock Classes="h2">A control into which the user can input text</TextBlock>

    <StackPanel Orientation="Horizontal"
              Margin="0,16,0,0"
              HorizontalAlignment="Center"
              Gap="16">
      <StackPanel Orientation="Vertical" Gap="8">
        <TextBox Text="Lorem ipsum dolor sit amet, consectetur adipiscing elit." Width="200" />
        <TextBox Width="200" Watermark="Watermark" />
        <TextBox Width="200" 
                 Watermark="Floating Watermark" 
                 UseFloatingWatermark="True"
                 Text="Lorem ipsum dolor sit amet, consectetur adipiscing elit."/>
        <TextBox Width="200" Text="Left aligned text" TextAlignment="Left" />
        <TextBox Width="200" Text="Center aligned text" TextAlignment="Center" />
        <TextBox Width="200" Text="Right aligned text" TextAlignment="Right" />
      </StackPanel>

      <StackPanel Orientation="Vertical" Gap="8">
        <TextBox AcceptsReturn="True" TextWrapping="Wrap" Width="200" Height="125"
                 Text="Multiline TextBox with TextWrapping.&#xD;&#xD;Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus magna. Cras in mi at felis aliquet congue. Ut a est eget ligula molestie gravida. Curabitur massa. Donec eleifend, libero at sagittis mollis, tellus est malesuada tellus, at luctus turpis elit sit amet quam. Vivamus pretium ornare est." />
        <TextBox AcceptsReturn="True" Width="200" Height="125"
                 Text="Multiline TextBox with no TextWrapping.&#xD;&#xD;Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus magna. Cras in mi at felis aliquet congue. Ut a est eget ligula molestie gravida. Curabitur massa. Donec eleifend, libero at sagittis mollis, tellus est malesuada tellus, at luctus turpis elit sit amet quam. Vivamus pretium ornare est." />
      </StackPanel>
    </StackPanel>
  </StackPanel>
</UserControl>