I hope someone can help.
I been struggling for days on this function, and it is quite hard to get an answer from the internet.
I am trying to get the location information of the child usb device, using CM_Get_DevNode_Property.
It works perfectly ok on Windows 7 x64, but fails on Windows 7 x86, with return code : CR_INVALID_FLAG
I searched and searched on the internet, but cannot find a good answer.
I do hope someone can.
Below is the code function, i used to get the location information. Thank you very much in advance.
Have a good day.
internal
void
EnumerateNode()
uint
inst;
int
result = NativeMethods.CM_Get_Child(
out
inst,
this
.DevicePtr,
0
);
while
(inst !=
0
)
int
nBytes =
4096
;
IntPtr
ptrInstanceBuf = Marshal.AllocHGlobal(nBytes);
NativeMethods.CM_Get_Device_ID(inst, ptrInstanceBuf, nBytes,
0
);
string
instanceID = Marshal.PtrToStringAuto(ptrInstanceBuf);
IntPtr
locationBuffer = Marshal.AllocHGlobal(nBytes);
ulong
size = (
ulong
)nBytes;
NativeMethods.DevPropKey location =
new
NativeMethods.DevPropKey();
location.guid =
new
Guid(
0xa45c254e
,
0xdf1c
,
0x4efd
,
0x80
,
0x20
,
0x67
,
0xd1
,
0x46
,
0xa8
,
0x50
,
0xe0
);
location.id = NativeMethods.Device_LocationInfoId;
ulong
propType =
0
;
string
locationInfo =
string
.Empty;
if
(NativeMethods.CM_Get_DevNode_Property(inst, location,
out
propType, locationBuffer,
ref
size,
0
) ==
0
)
locationInfo = Marshal.PtrToStringUni(locationBuffer);
UsbNode node =
new
UsbNode(instanceID, locationInfo, inst);
this
.UsbNodes.Add(node);
node.EnumerateNode();
NativeMethods.CM_Get_Sibling(
out
inst, inst,
0
);
finally
Marshal.FreeHGlobal(locationBuffer);
finally
Marshal.FreeHGlobal(ptrInstanceBuf);
Remarks
"This function is reserved for system use. Do not use this function in your class installers, co-installers, or device installation applications. Use
SetupDiGetDeviceProperty
instead."
Perhaps you have already tried this path.
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