Import dll problems

[squidge]

It seems like an FTDI library to me, which means it would be a plain simple 'C' library. Therefore you would need to use 'extern "C"' to reference the external dependancies in that library.

eg.

extern "C" void someFunction(int);

extern "C" void someFunction(int);

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[tom0485]

Like this?

class Q_DECL_IMPORT top16
{
public:
    top16();
 
    extern "C" int dllversion();
};

class Q_DECL_IMPORT top16
{
public:
    top16();

    extern "C" int dllversion();
};

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Then building the project returns the following:

... error: expected unqualified-id before string constant

I still don't really get how the linker should know which dll to use. Is it over the class name? All the tutorials that I found assume that you built the dll yourself or that you have at least the header file...

[squidge]

You can't use 'extern "C"' in a C++ class, that's a contradiction, and the compiler will complain. As for the DLL, you need to include the .LIB file with your project.

[tom0485]

A .lib file is not provided by the company. I think I rather try using the virtual com port to talk to the device. Thanks anyway!

[squidge]

Ok, but there are applications out there that provide .lib file output by parsing a .dll if the manufacturer doesn't provide a suitable one, but it does depend on the compiler.

An alternative is to use QLibrary to load the DLL at run time.