zoukankan      html  css  js  c++  java
  • c++函数指针用于回调函数

    #include "stdafx.h"

    typedef int (*func)(int,int);
    class data
    {
    public:
    data()
    {
    a=12;
    b=13;
    }
    ~data()
    {

    }
    static int setdata(int c,int d)
    {
    return c+d;
    }
    int a;
    int b;
    protected:
    private:

    };
    void test(func _func,void* _data)
    {
    data* mydata=(data*)_data;
    int c=(*_func)(mydata->a,mydata->b);
    int d=c;
    }
    int _tmain(int argc, _TCHAR* argv[])
    {

    data* mydata=new data();

    test(&mydata->setdata,(void*)mydata);
    return 0;
    }

     这里需要特别注意的是,我们的func也就是函数指针需要时全局或者类的静态函数,而测试函数test需要给我们的func参数,采用的是void*来转化。

    #include "stdafx.h"

    typedef int (*func)(int,int);
    class data
    {
    public:
    data()
    {
    a=12;
    b=13;
    }
    ~data()
    {

    }
    static int setdata(int c,int d)
    {
    return c+d;
    }
    int a;
    int b;
    protected:
    private:

    };
    void test(void* _func,void* _data)
    {
    data* mydata=(data*)_data;
    int c=(*(func)_func)(mydata->a,mydata->b);
    int d=c;
    }
    int _tmain(int argc, _TCHAR* argv[])
    {

    data* mydata=new data();

    test(&mydata->setdata,(void*)mydata);
    return 0;
    }

    后来改进了下,将将test的func指针也弄弄成了void*动态指定。

    #include "stdafx.h"

    typedef int (*func)(int,int);
    class data
    {
    public:
    data()
    {
    a=12;
    b=13;
    }
    ~data()
    {

    }
    static int setdata(int c,int d)
    {
    return c+d;
    }
    int a;
    int b;
    protected:
    private:

    };
    void* test(void* _func,void* _data)
    {
    data* mydata=(data*)_data;
    int c=(*(func)_func)(mydata->a,mydata->b);
    return (void*)&c;
    }
    int _tmain(int argc, _TCHAR* argv[])
    {

    data* mydata=new data();

    void* a =test(&mydata->setdata,(void*)mydata);
    int b=*(int*)a;
    return 0;
    }

    再次改进,新增返回值

  • 相关阅读:
    5.User Interface/Custom Components
    5.User Interface/Styles and Themes
    5.User Interface/Accessibility
    5.User Interface/Drag and Drop
    5.User Interface/Notifications
    5.User Interface/Dialogs
    Menu综合运用
    5.User Interface/ActionBar
    5.User Interface/Menu
    5.User Interface/Input Controls
  • 原文地址:https://www.cnblogs.com/chunlinge/p/3904365.html
Copyright © 2011-2022 走看看