'DeclarationPublicEvent LoadingData As EventHandler(Of LoadingDataEventArgs)
'UsageDim instance As DomainDataSource
Dim handler As EventHandler(Of LoadingDataEventArgs)
AddHandler instance.LoadingData, handler
This event is raised from Load and enables a handler to cancel the data loading before it starts. When a handler sets Cancel to true, the data loading will be aborted and a subsequent LoadedData event will not be raised. This differs slightly from canceling a data loading by way of CancelLoad.