我看一个DRIVER程序，发现。。。

发现用到一个函数：CM_Get_Parent（...），用来得到一个handle。  这个函数定义在程序中没有找到在DDK中也没有找到。为什么？

Setup, Plug  Play, Power Management: Windows 2000 DDK
CM_Get_Parent
CMAPI CONFIGRET WINAPI
  CM_Get_Parent(
    OUT PDEVINST pdnDevInst,
    IN DEVINST dnDevInst,
    IN ULONG ulFlags
    );
The CM_Get_Parent function is used to obtain a device instance handle to the parent node of a specified device node, in the local system's device tree.

Parameters
pdnDevInst
Caller-supplied address of a location to receive the first child's device instance handle.
dnDevInst
Caller-supplied device instance handle, obtained from the SP_DEVINFO_DATA structure that is used with the device installation functions.
Device instance handles can also be obtained by calling the following functions:

CM_Locate_DevNode
CM_Locate_DevNode_Ex
CM_Get_Child
CM_Get_Child_Ex
CM_Get_Parent
CM_Get_Parent_Ex
CM_Get_Sibling
CM_Get_Sibling_Ex

ulFlags
Not used, must be zero.
Return Value
If the operation succeeds, the function returns CR_SUCCESS. Otherwise, it returns one of the CR_-prefixed error codes defined in cfgmgr32.h.

See Also
CM_Get_Parent_Ex