title AsyncBase::OnCancel Method | Microsoft Docs ms.custom ms.date 11/04/2016 ms.reviewer ms.suite ms.technology cpp-windows ms.tgt_pltfrm ms.topic reference f1_keywords async/Microsoft::WRL::AsyncBase::OnCancel dev_langs C++ helpviewer_keywords OnCancel method ms.assetid 4bd0b68e-a9df-4913-9f6c-e093ed55c3f9 caps.latest.revision 3 author mikeblome ms.author mblome manager ghogen AsyncBase::OnCancel Method When overridden in a derived class, cancels an asynchronous operation. Syntax virtual void OnCancel( void ) = 0; Requirements Header: async.h Namespace: Microsoft::WRL See Also AsyncBase Class AsyncBase::Cancel Method