After inheriting from ScrollViewer, the child items are not rendered in the interface.

[qian-o]

Create a class named PreviewScrollViewer that inherits from ScrollViewer. Reference the namespace of PreviewScrollViewer in XAML, and use the control to place display content inside.

If only using ScrollViewer, there are no issues.

[timunie]

You need the Style for the custom control. If it should look like the normal one, use StyleKeyOverride