I'll try again: C++ DLL return values for VB

I thought I'd work off the thread I found, but Fordy locked the post whenever I tried to get some clarification on the resolution.
It seemed logical to keep related info in the same post so that if someone searched the board for the info they'd find it in one place.
Plus it was nice not having to start from square one. Oh well. Please add this odd rule, "Keep related info in completely seperate topics to create a mess" to the board rules so everyone is aware of it so they don't make the same mistake I did.


I was interested in finding out what the best return type would be for a C++ dll function so that it is usable in VB. I would prefer something that easily converts from a STL string.

The solution in the other post declared a

Code:

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String *

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but it did not show what header was included for this and the cpitalized S confuses me as to what it is, or perhaps it's something only used in .NET?

Thanks in advance for your replies. I would link to the other post for clarification since there was some good info there but I think that would anger the moderators and they would call it cross linking, or illegal cross referencing, or some other phrase that makes them feel really clever.

Quote:

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Originally posted by WebSnozz
I thought I'd work off the thread I found, but Fordy locked the post whenever I tried to get some clarification on the resolution.
It seemed logical to keep related info in the same post so that if someone searched the board for the info they'd find it in one place.
Plus it was nice not having to start from square one. Oh well. Please add this odd rule, "Keep related info in completely seperate topics to create a mess" to the board rules so everyone is aware of it so they don't make the same mistake I did.

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I closed the thread because nobody had added to it since the start of October last year.......Nobody likes old (seemingly settled) threads being reserected.

What people hate more is when someone post a question that could have been found by searching the board. Which I did, but I did not understand the solution, so I could have just started from square one and getting flamed because there is already a solution, then having to explain to everyone I already looked at that, but wasn't clear on the solution.

String there is just a typedef'd char (basing this off of the closed thread's context)

IE

typedef char String;

Which is really just a silly thing to do...

Cool, thanks.

I'm not sure what you have to do (I haven't read all of it yet) but lemme just tell you that .NET does NOT use char*. It uses unicode, __wchar_t, or wchar_t. That you can use with the .NET classes. To use a .NET string you use the prefix "S". So:

String *s=S"hey";

If you want to interface with them use the prefix "L" for unicode. If you want to use char* then you might want to check out:
System.Text.Encoding.ASCII

All this is for .NET. I dunno how helpful I was, but yea, hehehe

For C++ to VB6, use BSTR, or a variant type.

The old solution is .NET only. "String" is a .NET Framework datatype that is not available in normal C++ or VB6. String passing between C++ and VB6 is quite a mess, but your best bet is to go with BSTR.