How to pass parameters to dll?

问题

I have this function in DLL:

CPPLIBRARY_API int fnCPPLibrary(int a, int b)
{
    return a + b;
}

Main function:

int main(){
    FARPROC myCppProc;
    HINSTANCE hDll;
    DWORD L;
    int result;

    hDll = LoadLibrary("CPPLibrary");

    if (hDll != NULL){
        myCppProc = GetProcAddress(hDll, "fnCPPLibrary");

        if (myCppProc != NULL){
            result = myCppProc();
        cout <<"Result from library: " <<result;
        int a;
        }
    }
}

I can easly call fnCPPLibrary when it doesn't have arguments but how to pass params from program to that dll function? Is it simple or it requires some complicated code?

回答1:

The function pointer must have a signature that matches the function you're calling.

Not knowing what CPPLIBRARY_API is:

typedef int (*DLLFunc)(int, int);
DLLFunc myCppProc;
//...
myCppProc = (DLLFunc)GetProcAddress(hDll, "fnCPPLibrary");  // Cast to function pointer
myCppProc(1, 2);  // call function

I don't know what the qualifier CPPLIBRARY_API consists of, and it may be important (could be a calling convention -- you have to post this information). But in general, this is how you declare a function pointer and use GetProcAddress.

来源：https://stackoverflow.com/questions/27361479/how-to-pass-parameters-to-dll