IQueueCallbackStateChange interface

[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.]

An I/O queue object raises an event when it changes state. A driver can consume the event by registering the IQueueCallbackStateChange interface.


The IQueueCallbackStateChange interface inherits from the IUnknown interface. IQueueCallbackStateChange also has these types of members:


The IQueueCallbackStateChange interface has these methods.


The OnStateChange method is called when the state of the I/O queue object changes.



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.



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