title AsyncBase::OnClose 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::OnClose dev_langs C++ helpviewer_keywords OnClose method ms.assetid 96766450-c262-4611-8534-7d190b799142 caps.latest.revision 3 author mikeblome ms.author mblome manager ghogen AsyncBase::OnClose Method When overridden in a derived class, closes an asynchronous operation. Syntax virtual void OnClose( void ) = 0; Requirements Header: async.h Namespace: Microsoft::WRL See Also AsyncBase Class AsyncBase::Close Method