Assembly: System.Web (in system.web.dll)
The Page that raised the event.
An EventArgs that contains the event data.
The OnPagePreLoad method is used to control when data binding occurs within the life cycle of the page. It does this by setting the internal initialized state of the data-bound control. Because the control's initialized state is set during the PreLoad phase of the page's life cycle, the OnDataPropertyChanged event handler is called any time a data property of the control is changed after that phase, to signal that the control must re-bind to its data before rendering.
The OnPagePreLoad method is overridden by the DetailsView class to set the RequiresDataBinding property to true in cases where the HTTP request is a postback and view state is enabled but the data-bound control has not yet been bound. This scenario is common with controls such as Wizard and MultiView, where the visibility of the control is changed at run time.