On 2016/01/23 9:41 PM, Bart Smissaert wrote: > Using a .tlb file to access the sqlite3 functions from VB6. > Sofar when the arguments of the sqlite3 function are declared as int I have > been using > long in the IDL source to compile the tlb and this has been fine.
I'm not very familiar with the calling conventions and type declarations in VB6 - but if Long is the same as Int in bit-length and order, and the prototype parameter order and calling convention is the same as in C, then the types should match 100% all the time. If it isn't, then the fact that it has been working "fine" up to now is an accident of chance and not a good design choice. > sqlite3_compileoption_get is defined like this: > > const char *sqlite3_compileoption_get(int N); > > but using long here for the N argument causes a problem and it took me a > while > to unravel this problem. The .tlb compiles fine and all shows fine in the > object browser > in VB6, but the ActiveX can't be registered with Windows. > The solution was to use int or byte instead in the IDL for the N argument: It might be that in VB "Long" means 32 bits or 64 bits of Integer and may or may not support a sign bit (As I said, I don't know VB well), but I will be shocked if "Byte" in any language ends up meaning 32-bit signed integer (as I assume *Int* refers to in the C code you mention). I can't believe this solution is the right one, I feel like it "works" only by some jiggery-pokery from the compiler that was intended to smooth-over some other conversion or such. If it ain't the right solution, then the rest of your question is moot and my advice would be to first find the true bit-level matching type for c's int in VB, if however it /IS/ the right solution, my best advice would be to move away from VB and find a real programming environment (but I doubt this is the case).
