How to use CanContentRenderOutsideBounds on ListView - xaml

Question

I want to use CanContentRenderOutsideBounds on ListView. I know we can use it on ScrollViewer and that works, but it doesn't work on ListView. I've tried this:
<ListView ScrollViewer.CanContentRenderOutsideBounds="True">
<ListViewItem>
<Textblock>Content</Textblock>
</ListViewItem>
<!--This will be a lot of items-->
</ListView>
So, can we use CanContentRenderOutsideBounds for ListView? If don't, what can I do?

Answer 1

When you use ListView, it uses the default style, as follows:
<Style TargetType="ListView">
………
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListView">
<Border BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" BorderThickness="{TemplateBinding BorderThickness}" CornerRadius="{TemplateBinding CornerRadius}">
<ScrollViewer x:Name="ScrollViewer"
TabNavigation="{TemplateBinding TabNavigation}"
HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
…...>
<ItemsPresenter Header="{TemplateBinding Header}"
…… />
</ScrollViewer>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
As you can see, ListView has the built-in ScrollViewer, so you could use Visual Tree to find this ScrollViewer, then set its CanContentRenderOutsideBounds property to true in the Loaded event of ListView. Please refer to the following code.
Xaml code:
<ListView Height="100" x:Name="myListView" Loaded="ListView_Loaded">
<ListViewItem>
<TextBlock Text="item1"/>
</ListViewItem>
<ListViewItem>
<TextBlock Text="item2"/>
</ListViewItem>
// a lot of items
</ListView>
Code behind：
private void ListView_Loaded(object sender, RoutedEventArgs e)
{
var sc = FindChild<ScrollViewer>(myListView);
sc.CanContentRenderOutsideBounds = true;
}
public T FindChild<T>(DependencyObject parent)
{
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
if (child is T typedChild)
{
return typedChild;
}
var inner = FindChild<T>(child);
if (inner != null)
{
return inner;
}
}
return default;
}