WdfDeviceWdmGetAttachedDevice function (wdfdevice.h)

Artikel
02/22/2024

[Applies to KMDF only]

The WdfDeviceWdmGetAttachedDevice method returns the next-lower WDM device object in the device stack.

Syntax

PDEVICE_OBJECT WdfDeviceWdmGetAttachedDevice(
  [in] WDFDEVICE Device
);

Parameters

[in] Device

A handle to a framework device object.

Return value

WdfDeviceWdmGetAttachedDevice returns a pointer to a WDM DEVICE_OBJECT structure. If the specified object handle represents a physical device object (PDO), the method returns NULL.

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

Remarks

The pointer that the WdfDeviceWdmGetAttachedDevice method returns is valid until the framework device object is deleted. If the driver provides an EvtCleanupCallback function for the framework device object, the pointer is valid until the callback function returns.

Examples

The following code example creates a tracing message that contains pointers to the WDM device objects that represent a device's PDO, FDO, and next-lower device.

TraceEvents(
            TRACE_LEVEL_INFORMATION,
            DBG_PNP,
            "PDO(0x%p) FDO(0x%p), Lower(0x%p)\n",
            WdfDeviceWdmGetPhysicalDevice(device),
            WdfDeviceWdmGetDeviceObject(device),
            WdfDeviceWdmGetAttachedDevice(device)
            );

Requirements

Requirement	Value
Target Platform	Universal
Minimum KMDF version	1.0
Header	wdfdevice.h (include Wdf.h)
Library	Wdf01000.sys (see Framework Library Versioning.)
IRQL	<= DISPATCH_LEVEL
DDI compliance rules	DriverCreate(kmdf), KmdfIrql(kmdf), KmdfIrql2(kmdf), KmdfIrqlExplicit(kmdf)

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