VB2005 Short address pointer

2 May 2006 3:40 PM

Galen Somerville

A call to a third party dll, which will call back, requires an hWnd and a 16
bit sub address. Yes this was designed for VB6.

Addressof and delegates and all that good crap doesn't help.

The hWnd where the subroutine is located is no problem. But how can I
provide the subroutines address as a Short ??

GalenS

2 May 2006 4:14 PM

Mattias Sjögren

>A call to a third party dll, which will call back, requires an hWnd and a 16
>bit sub address. Yes this was designed for VB6.

VB6 also targets Win32 so I don't see how it could work there.

>The hWnd where the subroutine is located is no problem. But how can I
>provide the subroutines address as a Short ??

If you're running .NET 2.0 you can try calling
Marshal.GetFunctionPointerForDelegate(), truncate the result to
16-bits and see if it works.

Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
Please reply only to the newsgroup.

2 May 2006 5:34 PM

Galen Somerville

Show quote Hide quote

"Mattias Sjögren" <mattias.dont.want.spam@mvps.org> wrote in message
news:OPyyfPgbGHA.4892@TK2MSFTNGP02.phx.gbl...
> >A call to a third party dll, which will call back, requires an hWnd and a
> >16
>>bit sub address. Yes this was designed for VB6.
>
> VB6 also targets Win32 so I don't see how it could work there.
>
>
>>The hWnd where the subroutine is located is no problem. But how can I
>>provide the subroutines address as a Short ??
>
> If you're running .NET 2.0 you can try calling
> Marshal.GetFunctionPointerForDelegate(), truncate the result to
> 16-bits and see if it works.
>
>
> Mattias
>
> --
> Mattias Sjögren [C# MVP] mattias @ mvps.org
> http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
> Please reply only to the newsgroup.

My bad. In VB2005 it would be integer not short

VB6 code in bas module. The Call SetEventTable is immediately followed by
the 3rd party dll call WDU_Init

Dim eventTable As WDU_EVENT_TABLE

    Call SetEventTable(eventTable, AddressOf DeviceAttach, AddressOf
DeviceDetach)
    eventTable.pUserData = WD_VB_GetAddress(DevCtx, 1, 1)

    dwError = WDU_Init(hdriver, matchTable, 1, eventTable, _
        DEFAULT_LICENSE_STRING, WD_ACKNOWLEDGE, hWnd)

VB6 driver code bas module. It would appear that the AddressOf's could be
left out of the SetEventTable call and placed directly after the ='s below.

Public Sub SetEventTable(ByRef eventTable As WDU_EVENT_TABLE, ByVal attachCb
As Long, _
    ByVal detachCb As Long)
    eventTable.pfDeviceAttach = attachCb
    eventTable.pfDeviceDetach = detachCb
End Sub

Public Type WDU_EVENT_TABLE
    pfDeviceAttach As Long
    pfDeviceDetach As Long
    pfPowerChange As Long
    pUserData As Long
End Type

VB6 declares for callback procedures

Public Function DeviceAttach(ByVal hDevice As Long, ByRef pDeviceInfo As
WDU_DEVICE, _
    ByRef pUserData As DEVICE_CONTEXT) As Boolean
Public Sub DeviceDetach(ByVal hDevice As Long, ByRef pUserData As
DEVICE_CONTEXT)

GalenS