DLL调用,该如何处理

DLL调用
.H文件

C/C++ code

#ifndef dll1_H#define dll1_Hextern "C" int __declspec(dllexport)add(int x,int y);#endif

.CPP文件

C/C++ code

#include "dll1.h"int add(int x, int y){    int m = x + y;    return m;}

PB中定义：
function int add(int x, int y) library "dll1.dll" 

使用：cb_1.clicked:
messagebox('',add(1,2))
错误如下：
---------------------------
PowerBuilder Application Execution Error (R0042)
---------------------------
Application terminated.

Error: Specified argument type differs from required argument type at runtime in DLL function add.
 (invalid stack pointer on return from function call) at line 1 in clicked event of object cb_1 of w.
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确定  
---------------------------
计算机是双核的。

------解决方案--------------------
extern "C" int __declspec(dllexport)add(int x,int y);
改为
extern "C" _declspec(dllexport) int _stdcall add(int x,int y);

另外，PB中定义：
function int add(int x, int y) library "dll1.dll"
改为
function long add(long x, long y) library "dll1.dll"