calling a DLL function from VB with ByRef arguments 1

[IonelBurtan]

I have build a MFC DLL with 2 exported functions like this:
#define EXPORTED extern __declspec(dllexport)
EXPORTED LRESULT SetEnviron(LPCSTR strEnviron)
EXPORTED long GetEnviron(LPSTR strEnviron)

In VB I have the 2 declarations:
public declare sub SetEnviron lib "parser.dll"(ByVal strEnviron as String)
public declare function GetEnviron lib "parser.dll"(ByRef strEnviron as String) as Long

The body of the functions is dummy so I don't include them here. The problem is the first function(a simple setter), works just fine, but the second one fails with the following simptoms:

1. When I run the executable that call the function GetEnviron from inside VB I get error no 49 "Bad Dll calling convention"
2. When I run the executable that call the function GetEnviron from outside VB I get an error like "The memory cold not be read" then the program crushes.
3. When I run the executabile by debuging the DLL from VC++ line by line,I see that my function executes fine, puts the result in the byref passed argument, then after the last line of the function(return 0L it crushes with error "OLEOUT32 Access Violation".

 

[Cagliostro]

The standard calling convention is __stdcall. You should declare functions with this modificator. John Fill

ivfmd@mail.md

 

[IonelBurtan]

I have made the following modification in my GetEnviron function

#define EXPORTED extern __declspec(dllexport) __stdcall
long EXPORTED FAR PASCAL GetEnviron(LPSTR FAR strEnviron,long* lSize)

in VB:
Public Declare Function GetEnviron(ByVal strEnviron As String, ByRef lSize As Long) As Long

It works very fine, thanks to your help, an advice from a friend in France and some of my ideeas.(Now my function resembles a call to the API function GetComputerName)

Thank you