Visual C++ 2005 ( Passing value from VB6 to C++ DLL )

[C4C]

Hello,

First off, this is my first C++ project and as usual I have bit off more than I can chew, but that's my style of learning.

Is there any way to pass an array from VB6 to a C++ DLL function? If not is there any way to pass a value that can be used to dimension an array in the function?

I can pass the double values to the function but I cannot create an array to load them into because I have no const value with which to size an array. The DLL works just fine if I hard code the data in the program. When compared to the complexity of the DLL this issue leaves me feeling like I'm Stuck on Stupid. I have included the section of code below.

Thanks in advance for any help.

Ron Becker

/* The Array: Point_2 is a Type. */

Point_2 pts[]={Point_2(2.5849,-1.1012),
Point_2(2.4542,-.8248),
Point_2(1.7602,.6437),
Point_2(-.2112,1.2975),
Point_2(-1.388,2.0217),
Point_2(-2.7459,1.7602),
Point_2(-3.4399,.9555),
Point_2(-2.2531,.523),
Point_2(-1.388,-.8851),
Point_2(-1.9111,-2.0921),
Point_2(-.2414,-2.6956),
Point_2(.8047,-2.1927),
Point_2(1.901,-1.4283),
Point_2(2.4542,-.8248),
Point_2(2.5983,-.6676)};

/* Next Procedure: load array into vector. */

std::vector<Point_2> star(pts,pts+13);

 

[xwb]

Just pass the first value of the array. Since it is passed by location reference, which in C++ terms is by pointer (C++ references are not location references), C++ can access the rest of the array.

To get the size of the array use

sizeof (pts) / sizeof(pts[0])

You can do it by vectors but I have yet to try passing those to VB.

 

[C4C]

xwb,

Thanks for your advice. As you probably noticed the subject title did not reflect real issue. Originally I was passing the data with a string and then splitting the at "|" followed by splitting sub string at "/" and then using atof to get the double values. That works very well so I retained that part of the procedure. I enrolled in Vector 101 at cplusplus, God I love that site, and graduated at the top of my class. With that knowledge things got much easier and I now have the DLL completed. Now if I could just figure out how to edit my original post so that it showed the issue has been resolved.

Servo