How to make a StackPanel inside a ScrollViewer in WPF (or how else to add a load more button at the bottom of the elements in the ListView)?

Question

WPF

This is how I do it:

<ListView.Style>
                                                    <Style TargetType="ListView">
                                                                <Setter Property="Template">
                                                                    <Setter.Value>
                                                                        <ControlTemplate TargetType="ListView">

                                                                            <ScrollViewer x:Name="ScrollViewer" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Foreground="{TemplateBinding Foreground}" Padding="{TemplateBinding Padding}">
                                                                                <StackPanel>
                                                                                    <ItemsPresenter />
                                                                                    <Button Content="More" Name="moreButton"></Button>
                                                                                </StackPanel>
                                                                            </ScrollViewer>
                                                                        </ControlTemplate>
                                                                    </Setter.Value>
                                                                </Setter>
                                                    </Style>
                                                </ListView.Style>

but the ScrollViewer starts behaving inappropriately. scrolling does not work smoothly on one item, but perceives the entire stackpanel as a whole, skipping all the elements.
if instead of a StackPanel there is a Grid with a fixed Height, then this will not happen.
but Grid does not suit me, since the height of the ItemsPresenter, of course, is not known in advance

Answer 1

It is not clear from the question that your button should also scroll or should it be fixed there at the bottom of the control?

<ScrollViewer Grid.Row="1" VerticalScrollBarVisibility="Auto">
  <!-- Задаете шаблон отображения -->
  <ScrollViewer.Template>
     <ControlTemplate TargetType="{x:Type ScrollViewer}">
          <Grid>
             <ScrollContentPresenter /> <!-- Это область куда помещаются элементы, что будут скролировать -->
             <!-- Вместо этого комментария можно поместить кнопку, если не нужно, чтобы она скролировалась -->
             <ScrollBar x:Name="PART_VerticalScrollBar" Value="{TemplateBinding VerticalOffset}" Maximum="{TemplateBinding ScrollableHeight}"
                                   ViewportSize="{TemplateBinding ViewportHeight}" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"
                                   HorizontalAlignment="Right" Style="{DynamicResource ResourceKey=ScrollBarStyle}" />
                    </Grid>
       </ControlTemplate>
   </ScrollViewer.Template>
   <!-- А здесь помещаете все, что должно скролироваться -->
</ScrollViewer>