Static library and export function, export class

1. Static Link Library

Create a "Win32 project" and select Lib in "application settings. Create the Lib. h and Lib. cpp files. The source code of Lib. h and Lib. cpp is as follows:

// File: Lib. h # ifndef lib_h # define lib_hextern "C" int add (int x, int y); // declare as an external function of C compilation and connection mode # endif // file: Lib. CPP # include "Lib. H "int add (int x, int y) {return X + Y ;}

After compilation, the DLL and Lib files are generated. The following describes how to use them. The source code is as follows:

# Include <stdio. h> # include ".. \ Lib. H "# pragma comment (Lib ,".. \ debug \ libtest. lib ") // specify to connect int main (INT argc, char * argv []) {printf (" 2 + 3 = % d ", add (2, 3 ));}

2. Export Functions

Create a Win32 project and select DLL in application settings. Create two files: commendll. h and commendll. cpp. In commendll. h

namespace CommenDLL{         class MathFun         {         public:                   static __declspec(dllexport)double Add(double a, double b);                   static __declspec(dllexport)double Minus(double a, double b);         };}

In commendll. cpp

namespace CommenDLL{         double MathFun::Add(double a, double b)         {                   return a+b;         }         double MathFun::Minus(double a, double b)         {                   return a-b;         }}

3. Export class

In the header file of the same project

class __declspec(dllexport) Circle{public:         Circle(){};         ~Circle(){};         void   SetCenter(Point point);         void   SetRadius(int r);         double GetZhouChang();         double GetMianJi();private:         Point center;         int radius;};

CPP File

void Circle::SetCenter(Point point){    this->center.x = point.x;    this->center.y = point.y;}void Circle::SetRadius(int r){    this->radius = r;}double Circle::GetZhouChang(){    const double pi = 3.1415926;    return this->radius*pi*2;}double Circle::GetMianJi(){    const double pi = 3.1415926;    return pi*this->radius*this->radius;}

When calling, import the generated library and directly use its functions or classes.