Calling DLLs with pointers in Delphi -

i new delphi. have dll following exported function in it:

bool __stdcall myfunction(char * name, int * index)   

this code calls dll function in c++ works perfectly:

typedef void (winapi * myfunction_t)(char *, int *); void main() {     hmodule mydll = loadlibrary(l"c:\\mydll.dll");     myfunction_t myfunction = (myfunction_t)getprocaddress(mydll, "myfunction");      int index = 0;      myfunction("mystring", &index);  } 

i need same in delphi. here code, not working (myfunction gets called index variable doesn't receive appropriate value). code excerpt please ignore disorder. input appreciated!

type   tmyfunction= function(name: pchar; var index_ptr: integer): boolean; stdcall;  var   fmyfunction : tmyfunction;   : integer;   h: thandle;  begin   result := 0;   h := loadlibrary('c:\\mydll.dll');   fmyfunction := getprocaddress(h, 'myfunction');   if @fmyfunction <> nil   begin     fmyfunction('mystring', i);     result := i;   end;   freelibrary(h); end; 

first of assuming using c linkage extern "c" in case function defined in c++ translation unit.

if using delphi 2009 or later, need aware pchar pointer null-terminated wide character string.

to interop ansi c function need use:

type   tmyfunction= function(name: pansichar; var index: integer): boolean; stdcall; 

the c bool type best mapped longbool since it's not quite same delphi boolean:

type   tmyfunction= function(name: pansichar; var index: integer): longbool; stdcall; 

you don't need escape \ in strings can write:

h := loadlibrary('c:\mydll.dll'); 

you ought check errors on call loadlibrary and, technically, h hmodule rather thandle, although won't cause problems.

idiomatic delphi write:

  if assigned(fmyfunction)     fmyfunction('mystring', result); 

basically looks reasonable me i'm suspicious of character width.

hope helps.