IQueueCallbackStateChange::OnStateChange 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 OnStateChange method is called when the state of the I/O queue object changes.
Syntax
void OnStateChange(
[in] IWDFIoQueue *pWdfQueue,
[in] WDF_IO_QUEUE_STATE QueueState
);
Parameters
[in] pWdfQueue
A pointer to the IWDFIoQueue interface for the I/O queue object whose state changes.
[in] QueueState
A valid bitwise OR of WDF_IO_QUEUE_STATE-typed values that indicates status for the queue.
Return value
None
Remarks
A driver registers the IQueueCallbackStateChange interface when the driver calls the IWDFDevice::CreateIoQueue method to create an I/O queue or to configure the default I/O queue. The driver can optionally register the IQueueCallbackStateChange interface only for a manual queue. The driver must not register IQueueCallbackStateChange for a sequential or a parallel queue.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Windows |
| Header | wudfddi.h (include Wudfddi.h) |