WdfCollectionGetFirstItem function (wdfcollection.h)

Article
02/22/2024

[Applies to KMDF and UMDF]

The WdfCollectionGetFirstItem method returns a handle to the first object that is in an object collection.

Syntax

WDFOBJECT WdfCollectionGetFirstItem(
  [in] WDFCOLLECTION Collection
);

Parameters

[in] Collection

A handle to a collection object.

Return value

WdfCollectionGetFirstItem returns a handle to the object that is currently at the front of the specified collection's list of objects, or NULL if the list is empty.

A bug check occurs if the driver supplies an invalid object handle.

Remarks

For more information about object collections, see Framework Object Collections.

Examples

The following code example removes each item from a collection and deletes each item's object.

while ((subRequest = WdfCollectionGetFirstItem(hCollection)) != NULL) {
    WdfCollectionRemoveItem(
                            hCollection,
                            0
                            );
    WdfObjectDelete(subRequest);
}

Requirements

Requirement	Value
Target Platform	Universal
Minimum KMDF version	1.0
Minimum UMDF version	2.0
Header	wdfcollection.h (include Wdf.h)
Library	Wdf01000.sys (KMDF); WUDFx02000.dll (UMDF)
IRQL	<= DISPATCH_LEVEL
DDI compliance rules	DriverCreate(kmdf), KmdfIrql(kmdf), KmdfIrql2(kmdf), KmdfIrqlExplicit(kmdf)

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