c++ - 一个函数可以接收来自两个不同函数的两个参数吗？

Question

我有 2 个 void 函数(试图实现单选按钮)，我希望它们通过交换值将值发送到第三个函数。那个函数返回值给主函数？

MyScene.h 文件的代码

#ifndef __MY_SCENE_H__
#define __MY_SCENE_H__

#include "cocos2d.h"
USING_NS_CC;

class MyScene : public cocos2d::CCLayerColor
{
public:
    // Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphone
    virtual bool init();  

    // there's no 'id' in cpp, so we recommand to return the exactly class pointer
    static cocos2d::CCScene* scene();


    CCMenuItemToggle *R;

    CCMenuItemToggle *L;

    // a selector callback
    void swapL(CCObject *sender);
    void swapR(CCObject *sender);

    // implement the "static node()" method manually
    LAYER_NODE_FUNC(MyScene);
};

#endif // __HELLOWORLD_SCENE_H__

MyScene.cpp 文件的代码

#include "MyScene.h"

USING_NS_CC;

CCScene* MyScene::scene()
{
    // 'scene' is an autorelease object
    CCScene *scene = CCScene::node();

    // 'layer' is an autorelease object
    MyScene *layer = MyScene::node();

    // add layer as a child to scene
    scene->addChild(layer);

    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
bool MyScene::init()
{


    //////////////////////////////
    // 1. super init first
    if ( !CCLayerColor::initWithColor(ccc4(255,255,255,255) ))
    {
        return false;
    }

    //////////////////////////////
    // 2. add your codes below...

    CCSize WinSize= CCDirector::sharedDirector()->getWinSizeInPixels();

    CCSprite * fish=CCSprite::spriteWithFile("fish_bg.png");
    fish->setPosition(CCPointZero);
    fish->setAnchorPoint(CCPointZero);
    fish->setScaleX(WinSize.width/480);
    fish->setScaleY(WinSize.height/395);
    this->addChild(fish,0,0);


    CCSprite * on1=CCSprite::spriteWithFile("on.png");
    CCSprite * on2=CCSprite::spriteWithFile("on.png");
    CCSprite * on3=CCSprite::spriteWithFile("on.png");
    CCSprite * on4=CCSprite::spriteWithFile("on.png");

    CCSprite * off1=CCSprite::spriteWithFile("off.png");
    CCSprite * off2=CCSprite::spriteWithFile("off.png");
    CCSprite * off3=CCSprite::spriteWithFile("off.png");
    CCSprite * off4=CCSprite::spriteWithFile("off.png");


    CCMenuItem *LeftOn=CCMenuItemSprite::itemFromNormalSprite(on1,on2);
    CCMenuItem *RightOn=CCMenuItemSprite::itemFromNormalSprite(on3,on4);
    CCMenuItem *LeftOff=CCMenuItemSprite::itemFromNormalSprite(off1,off2);
    CCMenuItem *RightOff=CCMenuItemSprite::itemFromNormalSprite(off3,off4);

    CCMenuItemToggle *Left  = CCMenuItemToggle::itemWithTarget(this, menu_selector(MyScene::swapL),LeftOn,LeftOff,NULL);

    CCMenuItemToggle *Right = CCMenuItemToggle::itemWithTarget(this, menu_selector(MyScene::swapR),RightOn,RightOff,NULL);

    CCMenu *Radio= CCMenu::menuWithItems(Left,Right,NULL);

    Radio->alignItemsHorizontallyWithPadding(20);
    Radio->setPosition(ccp(WinSize.width/2,WinSize.height/2));


    this->addChild(Radio);
    //////////////////////////////
    return true;
}

void MyScene::swapL(CCObject *sender)
{
    L= (CCMenuItemToggle*)sender;
    CCLOG("L= %d",L->getSelectedIndex());

    int i=(L->getSelectedIndex());


}

void MyScene::swapR(CCObject *sender)
{
    R= (CCMenuItemToggle*)sender;

    CCLOG("R= %d",R->getSelectedIndex());
    int j=(R->getSelectedIndex());


}

Answer 1

是否有可能有 2 个 void 函数将参数发送到这 2 个函数中的第 3 个函数？

是的，这是可能的，为什么你认为这是不可能的？

Online Sample :

#include<iostream>

void doSomething(int &i)
{
    i = 10;
}

void doSomethingMore(int &j)
{
    j = 20;
}

void FinalDoSomething(const int i, const int j, int &k)
{
    k = i + j;
}

int main()
{
    int i = 0;
    doSomething(i);    

    int j = 0;
    doSomethingMore(j);

    int k = 0;
    FinalDoSomething(i,j,k);

    std::cout<<k;

    return 0;
}