WdfChildListRequestChildEject function (wdfchildlist.h)

• 02/26/2018
• 2 分钟可看完

[Applies to KMDF only]

The WdfChildListRequestChildEject method informs the framework that a specified device is about to be ejected from its docking station.

Syntax

BOOLEAN WdfChildListRequestChildEject(
  WDFCHILDLIST                                 ChildList,
  PWDF_CHILD_IDENTIFICATION_DESCRIPTION_HEADER IdentificationDescription
);

Parameters

ChildList

[in] A handle to a child list object.

IdentificationDescription

[in] A pointer to a caller-allocated WDF_CHILD_IDENTIFICATION_DESCRIPTION_HEADER structure.

Return value

WdfChildListRequestChildEject returns TRUE if the operation succeeds. If an input parameter is invalid, or if the framework cannot find the device in the child list, the method returns FALSE.

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

Remarks

A bus driver can call WdfChildListRequestChildEject or WdfPdoRequestEject to report that the driver has detected an attempt to eject one of its enumerated child devices from the device's docking station. For example, the driver might detect that a user has pushed an eject button.

If the driver is using dynamic bus enumeration and if the device's identification description is available, the driver can call WdfChildListRequestChildEject. If the framework device object for the device's PDO is available, the driver can call WdfPdoRequestEject.

The WdfChildListRequestChildEject method's IdentificationDescription parameter identifies the device that is being ejected. The device must be a member of the child list that the ChildList parameter represents.

The framework uses the identification description to locate the device in the child list.

For more information about child lists, see Dynamic Enumeration.

For more information about ejectable devices, see Supporting Ejectable Devices.

Examples

For a code example that uses WdfChildListRequestChildEject, see WdfChildListRetrieveNextDevice.

Requirements

See also

WDF_CHILD_IDENTIFICATION_DESCRIPTION_HEADER

WdfPdoRequestEject