Windows系统Python直接调用C++ DLL

环境：Window 10，VS 2019， Python 2.7.12, 64bit

1，打开 VS 2019，新建C++ Windows 动态链接库工程 Example，加入下列文件，如果Python是64位的则在VS中 Solution platforms 选择 x64 编译成64位的 DLL；

Example.h

#pragma once

#ifndef CPP_EXPORTS
#define CPP_EXPORTS
#endif

#ifdef CPP_EXPORTS
#define CPP_API _declspec(dllexport)
#else 
#define CPP_API _declspec(dllimport)
#endif

#include <iostream>
using namespace std;

#ifdef __cplusplus
extern "C"
{
#endif

    CPP_API int __cdecl getInt();
    CPP_API const char* __cdecl getString();
    CPP_API void __cdecl setString(const char* str);

#ifdef __cplusplus
}
#endif

Example.cpp

#include "pch.h"
#include "Example.h"

CPP_API int __cdecl getInt()
{
    return 5;
}

CPP_API const char* __cdecl getString()
{
    return "hello";
}

CPP_API void __cdecl setString(const char* str)
{
    cout << str << endl;
}

编译，得到 Example.dll

2, 打开 Command，cd 到 Example.dll 所在目录，输入 Python2,进入python环境

>>> from ctypes import *
>>> dll = CDLL("Example.dll")
>>> print dll.getInt()
5

>>> getStr = dll.getString
>>> getStr.restype = c_char_p
>>> pChar = getStr()
>>> print c_char_p(pChar).value
hello

>>> setStr = dll.setString
>>> setStr.argtypes = [c_char_p]
>>> pStr = create_string_buffer("hello")
>>> setStr(pStr)
hello
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