[TRNSYS-users] Error in cpp programming

[keilholz, werner]

Hi,

 

Using return values from functions defined in FORTRAN is problematic, due to the different stack model between the 2 languages. I solved the problem like this:

 

1.	Define a new function in TRNDll (basically a copy of the existing one, adapted as SUBROUTINE):

 

SUBROUTINE GETLABEL2(i,j, outLabel)   !i=unit #, j=label #

    !dec$ attributes dllexport :: getLabel2

    use TrnsysData

    use TrnsysConstants

    integer :: i,j,k,m,n

      character (len=*) :: outLabel

    

      m=0

      do k=1,N_LABELS

         if(LABEL_UNIT(k).eq.i) then

          m=m+1

              if(m.eq.j) then

             do n=1,maxLabelLength

                outLabel(n:n)=LABEL(n,k)

                 enddo

              endif

         endif

      enddo

end SUBROUTINE GETLABEL2

 

2. Use it in C++

 

 

     a) add to Trnsys.H:
extern "C" __declspec(dllimport) void _cdecl GETLABEL2(int* unit, int* label, 

char* outLabel, int* lOutLabel);


     b) in the code of the type:
      

  char theLabel[2000];

  int sizeLabel;

  int nLabel =1;

 

  GETLABEL2(&iunit, &nLabel, theLabel, &sizeLabel);

 

This will yield the name of the 1st (nLabel) special card padded with spaces (you have to scratch it out of "theLabel" by removing all trailing spaces.

 

If you do not want to modify trndll, you can use the method using External files described in my earlier post. 

 

Werner

 

 

________________________________

De : rgaray at labein.es [mailto:rgaray at labein.es] 
Envoyé : lundi 3 août 2009 15:01
À : keilholz, werner
Objet : RE: [TRNSYS-users] Error in cpp programming

 


Dear Keilholtz, 

Thank you for your help. 

We´re now trying to read the file in the "special card" way, but we´re heving some trouble, but i think this is the correct way. 

Could I ask for just some more help? 

I attach a proforma file. 

Would you please tell me in which way should I call the GetLabel() function? 

In cpp I´ve tried with the following: 

const char *cadena=""; 
cadena = getLabel(info[0],1); 

But it doesn´t work. 

Thank you. 

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