DLL的生成和使用

DLL的生成和使用

==========================

一、生成DLL动态库文件

1. 新建项目工程：DLLDemo(Visual C++ -> Win32 Console Application)

Application Settings -> type -> 选择DLL (Finished)

2. 添加 MyCode.h && MyCode.cpp 文件

MyCode.h

#ifndef _MYCODE_H_
#define _MYCODE_H_
#ifdef DLLDEMO1_EXPORTS
#define EXPORTS_DEMO _declspec( dllexport )
#else
#define EXPORTS_DEMO _declspec(dllimport)
#endif
extern "C" EXPORTS_DEMO int Add (int a , int b);
#endif

MyCode.cpp

#include "stdafx.h"
#include "MyCode.h"
int Add ( int a , int b )
{
       return ( a + b );
}

3. Build 生成DLL文件(附带lib文件)

二、使用DLL动态库(隐式调用 & 显示调用)

1. 在DLLDemo项目下新建工程(TestRun)(Visual C++ -> Win32 Console Application)
TestRun.cpp

// TestRun.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <iostream>
#include <windows.h>

//加载动态库(通过lib隐式加载) 01
//using namespace std;
//#pragma comment(lib, "DLLDemo.lib")
//extern "C" _declspec(dllimport) int Add(int a, int b);

//加载动态库(显示加载) 01
using namespace std;
typedef int (*AddFunc)(int a, int b);


int _tmain(int argc, _TCHAR* argv[])
{
    //加载动态库(通过lib隐式加载) 02
    //cout<<Add(2, 3)<<endl;

    //加载动态库(显示加载) 02
    HINSTANCE hDll = LoadLibrary("..\\Release\\DLLDemo.dll");
    if (hDll != NULL)
    {
        AddFunc add = (AddFunc)GetProcAddress(hDll, "Add");
        if (add != NULL)
        {
                cout<<add(2, 3)<<endl;
        }
        FreeLibrary(hDll);
    }

    system("pause");
    return 0;
}

 

warn:(字符集报错)

TestRun.cpp(25): error C2664: 'LoadLibraryW' : cannot convert parameter 1 from 'const char [23]' to 'LPCWSTR'

解决:(配置)

Character Set ( Configuration Properties -> General -> Project Defaults )
// Unicode 改为 多字节字符集
Use Unicode Character Set -> Use Multi-Byte Character Set

 

 

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