假设DLL文件名为 test.dll，函数 int add(int a.int b)
1.使用Windows API 的方式

extern "C" __declspec(dllexport) int add(int a, int b); // 定义函数typedef int (*AddFunction)(int, int); // 定义函数指针类型

    HMODULE hDll = LoadLibrary(L"test.dll");if (hDll != NULL) {AddFunction test= (AddFunctionc)GetProcAddress(hDll, "add");if (test!= NULL){// 调用函数int result = test(1,1);} else{std::cout<<"Failed to get function address";}FreeLibrary(hDll);}else {std::cout<<"Failed to load dll");}

2.QT 中使用QLibrary

extern "C" __declspec(dllexport) int add(int a, int b);

    // 加载 DLLQLibrary library("test"); // 不需要后缀名if (!library.load()) {// 获取函数指针AddFunction add = (AddFunction)library.resolve("add");if (add!==nullptr) {// 调用函数int result = add(3, 4);qDebug() << "Result of add(3, 4):" << result;}else{qDebug() << "Cannot load the function!";return -1;}}else{qDebug() << "Cannot load the library!";}