Cancel pending I/O operations

WIA applications can use the IWiaItemExtras::CancelPendingIO method (described in the Microsoft Windows SDK documentation) to cancel any pending I/O operations that the WIA minidriver may currently be processing. The IWiaItemExtras::CancelPendingIO method calls the IWiaMiniDrv::drvNotifyPnpEvent method with a WIA_EVENT_CANCEL_IO event. The WIA minidriver should cancel all current I/O operations and return to an idle state.

The IWiaItemExtras::CancelPendingIO method can be called at any time. It is recommended that all kernel-mode read or write operations use overlapped I/O. This allows an immediate cancellation to occur. WIA applications that are experiencing unexpected delays, or appear to be hanging, can call the IWiaItemExtras::CancelPendingIO method to attempt to return control back to the end user.