Interesting problem!

  • Thread starter Thread starter Steve
  • Start date Start date
S

Steve

Hi all,

I am having difficulty getting information from the system on USB devices
attached. The following is a snippet of the code:

Function declarations

Public Declare Function SetupDiGetClassDevs Lib "setupapi.dll" _
Alias "SetupDiGetClassDevsA" ( _
ByRef ClassGuid As Guid, _
ByVal Enumerator As String, _
ByVal hwndParent As Long, _
ByVal flags As Long) As Long

Public Declare Function SetupDiEnumDeviceInfo Lib "setupapi.dll" ( _
ByVal DeviceInfoSet As Long, _
ByVal MemberIndex As Long, _
ByRef DeviceInfoData As SP_DEVINFO_DATA) As Long


Part of the code:

Dim GUID_DEV_USB As Guid
Dim DevInfo As SP_DEVINFO_DATA

ReDim GUID_DEV_USB.data4(7)

With GUID_DEV_USB ' USB GUID
.Data1 = &HA5DCBF10
.Data2 = &H6530
.Data3 = &H11D2
.data4(0) = &H90
.data4(1) = &H1F
.data4(2) = &H0
.data4(3) = &HC0
.data4(4) = &H4F
.data4(5) = &HB9
.data4(6) = &H51
.data4(7) = &HED
End With

' Get device list
hDevInfo = SetupDiGetClassDevs(GUID_DEVCLASS_USB, vbNullString, vbNull,
DIGCF_PRESENT Or DIGCF_DEVICEINTERFACE)

DevInfo.cbSize = Len(DevInfo)

' Enumerate the devices attached
SetupDiEnumDeviceInfo(hDevInfo, I, DevInfo)

this snippet is part of a loop, I starts at 0

Here is the problem. hDevInfo returns an error. Well, not an error as
such, but a handle with the value of 9222812402617788072 (!).

The above code works in C, so why not VB .NET??

Many thanks,

Steve.
 
Steve said:
I am having difficulty getting information from the system on USB devices
attached. The following is a snippet of the code:

Function declarations

Public Declare Function SetupDiGetClassDevs Lib "setupapi.dll" _
Alias "SetupDiGetClassDevsA" ( _
Click to expand...

Skip the alias and use 'Declare Auto Function' instead.
ByRef ClassGuid As Guid, _
Click to expand...

Use Win32' 'GUID' structure here.
ByVal hwndParent As Long, _
Click to expand...

=> 'As IntPtr'.
ByVal flags As Long
Click to expand...

=> 'As Int32'.

) As Long

=> 'As IntPtr'.
Public Declare Function SetupDiEnumDeviceInfo Lib "setupapi.dll" ( _
ByVal DeviceInfoSet As Long, _
Click to expand...

=> 'As IntPtr'.
ByVal MemberIndex As Long, _
Click to expand...

=> 'As Int32'.
) As Long
Click to expand...

=> 'As Boolean'.
The above code works in C, so why not VB .NET??
Click to expand...

See above.
 
Many thanks for that Herfried, but the code still does not produce the
expected results.
With your changes, I now get what I consider a valid handle to a device
list. However, SetupDiEnumDeviceInfo always returns false and the error
code returned is ERROR_NO_MORE_ITEMS, even on the first call even though I
have 2 USB devices connected!

Any thoughts please?

Thanks again for your valuable help so far.

Steve.
 
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