Avalonia/samples/ControlCatalog/ScrollPage.xaml

<ResourceDictionary xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:controls="using:ControlCatalog">

  <ControlTheme x:Key="ScrollPage" TargetType="ContentPage">
    <Setter Property="Template">
      <ControlTemplate>
        <DockPanel>
          <ContentPresenter Name="PART_TopCommandBar"
                            DockPanel.Dock="Top"
                            HorizontalContentAlignment="Stretch"
                            IsVisible="False" />
          <ContentPresenter Name="PART_BottomCommandBar"
                            DockPanel.Dock="Bottom"
                            HorizontalContentAlignment="Stretch"
                            IsVisible="False" />

          <ScrollViewer Margin="20,20,5,0"
            HorizontalScrollBarVisibility="Disabled">
            <ContentPresenter Name="PART_ContentPresenter"
                            HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                            VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            Content="{TemplateBinding Content}"
                            ContentTemplate="{TemplateBinding ContentTemplate}"
                            CornerRadius="{TemplateBinding CornerRadius}" />
          </ScrollViewer>
        </DockPanel>
      </ControlTemplate>
    </Setter>
  </ControlTheme>
</ResourceDictionary>