学习Dll（五）--example from MSDN

Dll头文件

 

// MathFuncsDll.hnamespace MathFuncs{ class MyMathFuncs { public: // Returns a + b static __declspec(dllexport) double Add(double a, double b); // Returns a - b static __declspec(dllexport) double Subtract(double a, double b); // Returns a * b static __declspec(dllexport) double Multiply(double a, double b); // Returns a / b // Throws DivideByZeroException if b is 0 static __declspec(dllexport) double Divide(double a, double b); };}

 

Dll cpp文件

 

// MathFuncsDll.cpp// compile with: /EHsc /LD#include "MathFuncsDll.h"#include <stdexcept>using namespace std;namespace MathFuncs{ double MyMathFuncs::Add(double a, double b) { return a + b; } double MyMathFuncs::Subtract(double a, double b) { return a - b; } double MyMathFuncs::Multiply(double a, double b) { return a * b; } double MyMathFuncs::Divide(double a, double b) { if (b == 0) { throw new invalid_argument("b cannot be zero!"); } return a / b; }}

 

调用Dll的exe

 

在项目-->属性-->通用属性--> 框架和引用-->添加新引用：MathFuncsDll

                        配置属性-->C/C++ 常规-->附加包含目录：MathFuncsDll.h所在目录

 

 

 

// MyExecRefsDll.cpp// compile with: /EHsc /link MathFuncsDll.lib#include <iostream>#include "MathFuncsDll.h"using namespace std;int main(){ double a = 7.4; int b = 99; cout << "a + b = " << MathFuncs::MyMathFuncs::Add(a, b) << endl; cout << "a - b = " << MathFuncs::MyMathFuncs::Subtract(a, b) << endl; cout << "a * b = " << MathFuncs::MyMathFuncs::Multiply(a, b) << endl; cout << "a / b = " << MathFuncs::MyMathFuncs::Divide(a, b) << endl; return 0;}