Calling an unmanaged DLL from Visual Studio 2003 Visual Basic

Hall
I want to call an unmanaged dll, written in eMbedded Visual C++ 4.
from Visual Studio 2003 Visual Basic, for an application for Pocket PC 2003
I have tried with "Public Declare Function MSR3000_Open Lib "msr8800.dll" (..." and with the DllImport-statement
but the "MissingMethodException" occurs every time
I dont know how to set/declare the parameters

The function-declaration in the dll

typedef DWORD RET_STATUS
MSR8800_API RET_STATUS Msr3000_Open(TCHAR *ptrSerialPort, TCHAR *ptrDllVersion
TCHAR *ptrFirmwareVersion, void *pPortHandle


I have a program written in eMbedded Visual C++ 4.0 and the call from that program looks like this

DWORD rs
TCHAR szPort[] = _T("COM1:"); // Serial Por
TCHAR szDll[40]; // to receive version inf
TCHAR szFirm[40]; // to receive firmware versio
TCHAR szDummy[20]; // for unused parameter
rs = Msr3000_Open(szPort,szDll, szFirm, szDummy)

Regards Ã…ke

Hi Ã…ke

Working with unmanaged dll calls is sometimes quite tricky. There are
a few simple steps that you should verify

1. Does the executable locate the correct dl
2. Check the exported symbols with dumpbin /export

I'm not completely shure but I think that missing method exceptions only
occur when the runtime fails to locate a managed method, and that the
exception that you probably should encounter if there is a missmatch
between managed/unmanaged code is EntrypointNotFoundException
(but I can't verify this at this point

Best Regards, Daniel Peterson

The dumpbin /exports give me
10 9 0000100F ?Msr3000_Open@@YAKPAG00PAX@

It dont say me a thing

The following call give me "A managed InvalidCastException"

<DllImport("msr8800.dll", CallingConvention:=CallingConvention.Winapi,
CharSet:=CharSet.Unicode, EntryPoint:="Msr3000_Open")>
Public Shared Function
Msr3000_OpenW(ByVal ptrSerialPort As Byte, ByVal ptrDllVersion As Byte,
ByVal ptrFirmwareVersion As Byte, ByVal pPortHandle As Byte) As UInt3
End Functio

Public svar_open As UInt3
Public svar_close As Int3
Public szPort As Strin
Public szDll As Strin
Public szFirm As Strin
Public szDummy As Strin

Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Clic
szPort = "COM1:
svar = Form1.Msr3000_OpenW(szPort, szDll, szFirm, szDummy
svar_open = Form1.Msr3000_OpenW(szPort, szDll, szFirm, szDummy

Another question: How do you write the right path on Pocket PC 2003 for msr8800.dll

http://msdn.microsoft.com/mobility/...f/FAQ/default.a
spx#6.1

--
--
Alex Yakhnin .NET CF MVP
www.intelliprog.com | www.opennetcf.org

"AkeK" <anonymous@discussions.microsoft.com> wrote in message
news:E9BE8C4A-21BC-4A31-8EC1-D7E3DFF78187@microsoft.com...
>
> The dumpbin /exports give me:
> 10 9 0000100F ?Msr3000_Open@@YAKPAG00PAX@Z
>
> It dont say me a thing!
>
> The following call give me "A managed InvalidCastException":
>
> <DllImport("msr8800.dll", CallingConvention:=CallingConvention.Winapi, _
> CharSet:=CharSet.Unicode, EntryPoint:="Msr3000_Open")> _
> Public Shared Function _
> Msr3000_OpenW(ByVal ptrSerialPort As Byte, ByVal ptrDllVersion As
Byte, _
> ByVal ptrFirmwareVersion As Byte, ByVal pPortHandle As Byte) As
UInt32
> End Function
>
> Public svar_open As UInt32
> Public svar_close As Int32
> Public szPort As String
> Public szDll As String
> Public szFirm As String
> Public szDummy As String
>
> Private Sub Button1_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Button1.Click
> szPort = "COM1:"
> svar = Form1.Msr3000_OpenW(szPort, szDll, szFirm, szDummy)
> svar_open = Form1.Msr3000_OpenW(szPort, szDll, szFirm, szDummy)
>
> Another question: How do you write the right path on Pocket PC 2003 for
msr8800.dll ?
>

The name is mangled, and your declaration cannot find it.

http://msdn.microsoft.com/mobility/...pbinpinvoke.asp

--
Chris Tacke, eMVP
Co-Founder and Advisory Board Member
www.OpenNETCF.org
---
Windows CE Product Manager
Applied Data Systems
www.applieddata.net


"AkeK" <anonymous@discussions.microsoft.com> wrote in message
news:E9BE8C4A-21BC-4A31-8EC1-D7E3DFF78187@microsoft.com...
>
> The dumpbin /exports give me:
> 10 9 0000100F ?Msr3000_Open@@YAKPAG00PAX@Z
>
> It dont say me a thing!
>
> The following call give me "A managed InvalidCastException":
>
> <DllImport("msr8800.dll", CallingConvention:=CallingConvention.Winapi, _
> CharSet:=CharSet.Unicode, EntryPoint:="Msr3000_Open")> _
> Public Shared Function _
> Msr3000_OpenW(ByVal ptrSerialPort As Byte, ByVal ptrDllVersion As
Byte, _
> ByVal ptrFirmwareVersion As Byte, ByVal pPortHandle As Byte) As
UInt32
> End Function
>
> Public svar_open As UInt32
> Public svar_close As Int32
> Public szPort As String
> Public szDll As String
> Public szFirm As String
> Public szDummy As String
>
> Private Sub Button1_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Button1.Click
> szPort = "COM1:"
> svar = Form1.Msr3000_OpenW(szPort, szDll, szFirm, szDummy)
> svar_open = Form1.Msr3000_OpenW(szPort, szDll, szFirm, szDummy)
>
> Another question: How do you write the right path on Pocket PC 2003 for
msr8800.dll ?
>

Hallo and thanks for all help
I havent solved it yet, but I going to try on wednesda
Best regards Ã…ke

http://www.alexfeinman.com/download...c=MsrReader.zip
But you will be better off obtaining Symbol Mobility .NET SDK that contains
predefined classes for MSR 3000

"AkeK" <anonymous@discussions.microsoft.com> wrote in message
news:CA1CAA05-5495-4B89-9C71-85CD34E7BDB5@microsoft.com...
> Hallo
> I want to call an unmanaged dll, written in eMbedded Visual C++ 4.0
> from Visual Studio 2003 Visual Basic, for an application for Pocket PC
2003.
> I have tried with "Public Declare Function MSR3000_Open Lib "msr8800.dll"
(..." and with the DllImport-statement,
> but the "MissingMethodException" occurs every time.
> I dont know how to set/declare the parameters.
>
> The function-declaration in the dll:
>
> typedef DWORD RET_STATUS;
> MSR8800_API RET_STATUS Msr3000_Open(TCHAR *ptrSerialPort, TCHAR
*ptrDllVersion,
> TCHAR *ptrFirmwareVersion, void *pPortHandle)
> {
>
> I have a program written in eMbedded Visual C++ 4.0 and the call from that
program looks like this:
>
> DWORD rs;
> TCHAR szPort[] = _T("COM1:"); // Serial Port
> TCHAR szDll[40]; // to receive version info
> TCHAR szFirm[40]; // to receive firmware version
> TCHAR szDummy[20]; // for unused parameters
> rs = Msr3000_Open(szPort,szDll, szFirm, szDummy);
>
> Regards Åke

Thanks for the answer, I think this is what I need
Regards Ã…ke