Hi,

I am writing a COM using VC.Net. I have to call some DLLs which were writen
in VC++ 6. When I call some functions in the DLLs, some run well but some
cannot. I always get the same error:

First-chance exception at 0x77e6d756 in VB_Test.exe: Microsoft C++

WSDATA has encountered a problem: Error loading library wsmsdata

I tried use the same routines in a console applaction, there is no problem.
The document of the DLLs has mentioned:
All of the functions are exported with the __stdcall calling convention

But in my console application, I just use the default setting: __cdecl and
it works very well. For the COM, no matter which setting cannot work.

What's wrong?

Thank you for any comment.

Jerry

The called DLL has thrown a C++ exception of the type
CEntryPointException. This is a user-defined exception type. Presumably,
it cannot find wsmsdata, whatever that might be. Apparently, you are
calling into WSDATA.dll which tries to load wsmsdata.dll, fails and
reports it by throwing an exception.

Are you running an application that works and the one that does not from
different directories? Even if wsdata.dll and wsmsdata.dll are in the
same directory, one may not find the other because LoadLibrary looks in
the directory of the EXE, not that of the DLL. Try running your
application from the directory containing both DLLs, or add their
directory to PATH.
--
With best wishes,
    Igor Tandetnik

"For every complex problem, there is a solution that is simple, neat,
and wrong." H.L. Mencken

Igor,

Thank you vrey much for your help. I fixed it. The reason is the COM client
cannot find the DLL. After I copied the DLLs to the directory of the client
application, it works well.

Thank you again.

Jerry