DLL的导出和调用

动态链接库在C++中非常重要，写了一个简单的例子用于DLL的导出和调用。

DLL的生成

头文件

#include<iostream>
#include<stdexcept> 
using namespace std;#define TESTAPI __declspec(dllexport)// 函数定义
extern "C" {TESTAPI int add(int a, int b);TESTAPI int sub(int a, int b);TESTAPI int mul(int a, int b);TESTAPI int div_(int a, int b);
}

源文件

#include"test.h"int add(int a, int b) {return a + b;
}int sub(int a, int b) {return a - b;
}int mul(int a, int b) {return a * b;
}int div_(int a, int b) {try {if (b == 0) {throw std::runtime_error("Division by zero error!"); // 抛出异常}return a / b;}catch (const std::runtime_error& e) {cout << "Error: " << e.what() << endl; // 捕获并处理异常return 0; // 或根据需求返回其他值}
}

配置类型DLL

生成DLL

‘

DLL的调用

把生成的test1.dll放在测试工程test_useDll的目录下

调用DLL中的接口

#include <iostream>
#include <windows.h>  
using namespace std;// 声明函数指针
typedef int(*AddFunc)(int, int);
typedef int(*SubFunc)(int, int);
typedef int(*MulFunc)(int, int);
typedef int(*DivFunc)(int, int);int main() {// 加载DLLHINSTANCE hDLL = LoadLibraryA("test1.dll");if (!hDLL) {cout << "Failed to load DLL." << endl;return 1;}// 获取函数地址AddFunc add = (AddFunc)GetProcAddress(hDLL, "add");SubFunc sub = (SubFunc)GetProcAddress(hDLL, "sub");MulFunc mul = (MulFunc)GetProcAddress(hDLL, "mul");DivFunc div_ = (DivFunc)GetProcAddress(hDLL, "div_");if (!add || !sub || !mul || !div_) {cout << "Failed to get function address." << endl;FreeLibrary(hDLL);return 1;}// 调用DLL中的函数int a = 10, b = 5;cout << "add(a, b) = " << add(a, b) << endl;cout << "sub(a, b) = " << sub(a, b) << endl;cout << "mul(a, b) = " << mul(a, b) << endl;cout << "div_(a, b) = " << div_(a, b) << endl;// 释放DLLFreeLibrary(hDLL);return 0;
}

结果