topic std::string -> GS::uchar_t gdl parameter in Archicad C++ API

std::string -> GS::uchar_t gdl parameter

Anonymous — Thu, 29 Sep 2022 08:10:09 GMT

Hi there!

I think i have a simple problem, but i couldn't get over it by myself....

I have an std::string parameter which is came from a csv file through ifstream::getline. And i have to change a library element string parameter, which is uchar_t *. But i couldn't get it converted...

so here is what i tried:


//these are predefined
   std::string line;
   Int32 id;
   char paramname[32];

API_ChangeParamType  chgParam;

BNZeroMemory(&chgParam, sizeof(API_ChangeParamType));

chgParam.index = id;
strcpy(chgParam.name, paramname);
GS::ucscpy(chgParam.uStrValue, GS::UniString(line.c_str()).ToUStr().Get()); //GSReporter crash

but it is crashing during ucscpy.
So how should i transfere my string to get it working? I always had issues with string especially unistrings/unichars.

Re: std::string -> GS::uchar_t gdl parameter

Tibor Lorantfy — Tue, 08 Oct 2019 08:33:02 GMT

Hi,

This should work:

GS::uchar_t bufferUStr[API_UAddParStrLen];
GS::ucsncpy (bufferUStr, GS::UniString (line.c_str()).ToUStr().Get(), API_UAddParStrLen - 1);
chgParam.uStrValue = bufferUStr;

Just make sure, that bufferUStr will live till you use the chgParam

A little explanation:
uStrValue is a simple pointer, it just points to somewhere. That's why you cannot write characters into it and you got crash report immediately. You have to set the pointer to an existing array of characters.

Re: std::string -> GS::uchar_t gdl parameter

Anonymous — Tue, 08 Oct 2019 09:01:55 GMT

Thank you very much this is helped a lot to understand pointers as well because i didn't used a lot c++.