IDeviceIoControl::CancelOperation method (deviceaccess.h)

The CancelOperation method attempts to cancel a previously issued call by using the DeviceIoControlAsync method.

Syntax

HRESULT CancelOperation(
  [in] ULONG_PTR cancelContext
);

[in] cancelContext

The cancel context that a previous call to DeviceIoControlAsync returned.

This method supports standard return values, in addition to these:

Return code	Description
S_OK	The operation was still outstanding, and cancellation was attempted.
ERROR_NOT_FOUND	The operation was no longer outstanding.

Regardless of whether cancellation is successful, the result of the operation is available in the callback that's provided to the asynchronous call.