请问为什么下面代码会出错。VC调用DELPHI DLL.

Question

DELPHI：
================================
library DCToJpg;
uses  SysUtils,  Classes,  windows,  Graphics,  Jpeg;
function add(i:Pinteger;j:Pinteger):integer;stdcall;
begin
 result:=i^+j^;
end;
exports
Add name 'Add';
begin
end.
VC调用部分：
typedef long (* _add)(long* a,long* b); 
void CDllCallDlg::OnOK() 
{
HINSTANCE hLibrary;
_add add; hLibrary=LoadLibrary("DCToJpg.dll");
add=(_add)GetProcAddress(hLibrary,"Add");
long i;
long x(1),y(-2);i= (*add)(&x,&y);
FreeLibrary(hLibrary); 
CString s;
s.Format("%d",i);
::AfxMessageBox(s);

CDialog::OnOK();
}

Answer 1

i= (*add)(&x,&y);==>
i=add(&x,&y)

Answer 2

function add(i:Pinteger;j:Pinteger):integer;stdcall;
--------------------------------------------^^^^^^^^stdcall改掉

Answer 3

void CDllCallDlg::OnOK() 
{
HINSTANCE hLibrary;
_add add; hLibrary=LoadLibrary("DCToJpg.dll");
if (hLibrary == NULL)
{
error();
}
add=(_add)GetProcAddress(hLibrary,"Add");
if (add == NULL
{
error();
}
long i;
long x(1),y(-2);i= add(&x,&y);
FreeLibrary(hLibrary); 
CString s;
s.Format("%d",i);
::AfxMessageBox(s);

CDialog::OnOK();
}