IWDFIoRequest2::IsCanceled method (wudfddi.h)
[Warning: UMDF 2 is the latest version of UMDF and supersedes UMDF 1. All new UMDF drivers should be written using UMDF 2. No new features are being added to UMDF 1 and there is limited support for UMDF 1 on newer versions of Windows 10. Universal Windows drivers must use UMDF 2. For more info, see Getting Started with UMDF.]
The IsCanceled method determines whether the I/O manager has attempted to cancel an I/O request.
Syntax
BOOL IsCanceled();
Return value
IsCanceled returns TRUE if the I/O manager has attempted to cancel the I/O request. This method returns FALSE for any of the following reasons:
- The I/O manager has not attempted to cancel the request.
- The calling driver does not own the request.
- The calling driver has called the IWDFIoRequest::MarkCancelable method.
Remarks
If your driver has not called IWDFIoRequest::MarkCancelable to register an IRequestCallbackCancel::OnCancel callback function, but if you want your driver to determine if the I/O manager has attempted to cancel an I/O request, the driver can call IsCanceled.
A driver can call IsCanceled for a request only if the driver owns the I/O request. If the driver has called IWDFIoRequest::MarkCancelable, it must call IWDFIoRequest::UnmarkCancelable before calling IsCanceled.
If IsCanceled returns TRUE, your driver should cancel the request by calling IWDFIoRequest::Complete with the CompletionStatus parameter set to HRESULT_FROM_WIN32(ERROR_OPERATION_ABORTED).
For more information about IsCanceled, see Canceling I/O Requests.
Examples
In the following code example, if IsCanceled returns TRUE, the driver completes the I/O request by calling IWDFIoRequest::Complete with a completion status of HRESULT_FROM_WIN32(ERROR_OPERATION_ABORTED).
if (fxRequest2->IsCanceled())
{
fxRequest2->Complete(HRESULT_FROM_WIN32(ERROR_OPERATION_ABORTED));
}
...
Requirements
| Requirement | Value |
|---|---|
| End of support | Unavailable in UMDF 2.0 and later. |
| Target Platform | Desktop |
| Minimum UMDF version | 1.9 |
| Header | wudfddi.h (include Wudfddi.h) |
| DLL | WUDFx.dll |