On-demand loading provides a smooth and seamless scrolling experience with UI virtual components. This feature is useful when your application users have to work with large amounts of data. It enables the control to download only the information that needs to be displayed on the screen as opposed to the whole data providing much faster loading and much smoother end user experience.
To enable powerful data virtualization in your Silverlight applications, simply use VirtualQueryableCollectionView and bind to other Silverlight UI controls.
This collection is mainly intended to serve ReadOnly scenarios. When using VirtualQueryableCollectionView for Silverlight, you can benefit from the built-in selection, sorting and filtering functionalities. However, full support for extended selection and filtering is not provided.