cocos2d-x ScrollView、TableView

转自：http://codingnow.cn/cocos2d-x/1024.html

在游戏和应用中经常要实现左右滑动展示游戏帮助、以列表显示内容的UI效果，就像android中的Gallery和ListView。本文通过CCScrollView和CCTableView分别来实现这两个效果，基于cocos2d-x 2.0.4版本。
首先来简单了解一下这两个东东，CCScrollView本身是一个CCLayer，而CCTableView是CCScrollView的子类，这是引擎已经帮我们封装好了的，CCTableView可以设置成横向和纵向，用它可以实现类似于Gallery和ListView的效果。
1. 首先实现游戏帮助界面
(1) 创建头文件GalleryLayer.h

#ifndef GALLERY_LAYER_H
#define GALLERY_LAYER_H

#include "cocos2d.h"
#include "SimpleAudioEngine.h"
#include "cocos-ext.h"

USING_NS_CC;
USING_NS_CC_EXT;

class GalleryLayer : public cocos2d::CCLayer ,public CCScrollViewDelegate
{
public:
    virtual bool init();  

    void menuCloseCallback(CCObject* pSender);

    CREATE_FUNC(GalleryLayer);

public:
    //scrollview滚动的时候会调用
    void scrollViewDidScroll(CCScrollView* view);
    //scrollview缩放的时候会调用
    void scrollViewDidZoom(CCScrollView* view);

    virtual void onEnter();
    virtual void onExit();

    virtual bool ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent);
    virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);
    virtual void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent);
    virtual void ccTouchCancelled(CCTouch *pTouch, CCEvent *pEvent);

private:
    //根据手势滑动的距离和方向滚动图层
     void adjustScrollView(float offset);
     CCScrollView *m_pScrollView;
     CCPoint m_touchPoint;
     int m_nCurPage;
};

#endif

类GalleryLayer继承了CCScrollViewDelegate，实现了它的两个纯虚函数，主要是为了当scrollview滚动和缩放时回调这两函数，这样我们就可以在这两函数中做相关操作了。

(2) 看源文件GalleryLayer.cpp

#include "GalleryLayer.h"
#include "ListViewLayer.h"

using namespace cocos2d;
using namespace cocos2d::extension;

bool GalleryLayer::init()
{
    bool bRet = false;
    do
    {
       CC_BREAK_IF( !CCLayer::init() );

       m_nCurPage = ;
       CCSize visibleSize = CCDirector::sharedDirector()->getVisibleSize();
       CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();

       CCLayer *pLayer = CCLayer::create();
       char helpstr[] = {};
       for (int i = ; i <= ; ++ i)
       {
           memset(helpstr, , sizeof(helpstr));
           sprintf(helpstr,"bg_%02d.png",i);
           CCSprite *pSprite = CCSprite::create(helpstr);
           pSprite->setPosition(ccp(visibleSize.width * (i-0.5f), visibleSize.height / ));
           pLayer->addChild(pSprite);
       }

       m_pScrollView = CCScrollView::create(CCSizeMake(, ), pLayer);
       m_pScrollView->setContentOffset(CCPointZero);
       m_pScrollView->setTouchEnabled(false);
       m_pScrollView->setDelegate(this);
       m_pScrollView->setDirection(kCCScrollViewDirectionHorizontal);
       pLayer->setContentSize(CCSizeMake(*, ));

       this->addChild(m_pScrollView);

       CCSpriteFrameCache *pCache =  CCSpriteFrameCache::sharedSpriteFrameCache();

       pCache->addSpriteFrame(CCSpriteFrame::create("button_normal.png",CCRectMake(, , , )),"button_normal.png");
       pCache->addSpriteFrame(CCSpriteFrame::create("button_selected.png",CCRectMake(, , , )),"button_selected.png");
       for (int i = ; i <= ; ++ i)
       {
           CCSprite *pPoint = CCSprite::createWithSpriteFrameName("button_normal.png");
           pPoint->setTag(i);
           pPoint->setPosition(ccp( origin.x + (visibleSize.width -  * pPoint->getContentSize().width)/ + pPoint->getContentSize().width * (i-), origin.y + ));
           this->addChild(pPoint);
       }
        CCSprite *pPoint = (CCSprite *)this->getChildByTag();
        pPoint->setDisplayFrame(pCache->spriteFrameByName("button_selected.png"));

        bRet = true;
    }while();

    return bRet;

}

void GalleryLayer::menuCloseCallback(CCObject* pSender)
{

}

void GalleryLayer::scrollViewDidScroll(cocos2d::extension::CCScrollView *view)
{
    CCLOG("scroll");
}

void GalleryLayer::scrollViewDidZoom(cocos2d::extension::CCScrollView *view)
{
    CCLOG("zoom");
}

void GalleryLayer::onEnter()
{
    CCLayer::onEnter();
    CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, , false);
}

void GalleryLayer::onExit()
{
    CCDirector::sharedDirector()->getTouchDispatcher()->removeDelegate(this);
    CCLayer::onExit();
    CCSpriteFrameCache::sharedSpriteFrameCache()->removeUnusedSpriteFrames();
}

bool GalleryLayer::ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent)
{
    m_touchPoint = CCDirector::sharedDirector()->convertToGL(pTouch->getLocationInView());
    return true;
}

void GalleryLayer::ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent)
{

}

void GalleryLayer::ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent)
{
    CCPoint endPoint = CCDirector::sharedDirector()->convertToGL(pTouch->getLocationInView());
    float distance = endPoint.x - m_touchPoint.x;
    if(fabs(distance) > )
    {
        adjustScrollView(distance);
    }
}

void GalleryLayer::ccTouchCancelled(cocos2d::CCTouch *pTouch, cocos2d::CCEvent *pEvent)
{
    CCPoint endPoint = CCDirector::sharedDirector()->convertToGL(pTouch->getLocationInView());
    float distance = endPoint.x - m_touchPoint.x;
    if(fabs(distance) > )
    {
        adjustScrollView(distance);
    }
}

void GalleryLayer::adjustScrollView(float offset)
{
    CCSize visibleSize = CCDirector::sharedDirector()->getVisibleSize();
    CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();
    CCSpriteFrameCache *pCache =  CCSpriteFrameCache::sharedSpriteFrameCache();
    CCSprite *pPoint = (CCSprite *)this->getChildByTag(m_nCurPage);
    pPoint->setDisplayFrame(pCache->spriteFrameByName("button_normal.png"));
    if (offset<)
    {
        m_nCurPage ++;
    }else
    {
        m_nCurPage --;
    }

    if (m_nCurPage <)
    {
        m_nCurPage = ;
    }

    if(m_nCurPage > )
    {
        CCLayer *pLayer = ListViewLayer::create();
        CCScene *pScene = CCScene::create();
        pScene->addChild(pLayer);
        CCDirector::sharedDirector()->replaceScene(pScene);
    }
    else
    {
        pPoint = (CCSprite *)this->getChildByTag(m_nCurPage);
        pPoint->setDisplayFrame(pCache->spriteFrameByName("button_selected.png"));
        CCPoint  adjustPos = ccp(origin.x - visibleSize.width * (m_nCurPage-), );
        m_pScrollView->setContentOffset(adjustPos, true);
    }
}

这里一共有三张图，是从捕鱼达人中拿出来的背景图，当滚完三张图时就跳转到ListViewLayer场景去，上面的代码比较容易懂。
首先创建一个CCLayer，包含三张背景图，设置CCLayer的ContentSize，并设置三张图片的位置
然后设置CCLayer为CCScrollview的内容，并设置CCScrollView的显示区域。
最后根据用户滑动的方向和距离，通过设置scrollview的setContentOffset，滚动视图。
CCScrollview.h文件中封装了一个枚举类型，一共有四个方向，常用横向和纵向，这里使用了横向。

typedef enum {
    kCCScrollViewDirectionNone = -,
    kCCScrollViewDirectionHorizontal = ,
    kCCScrollViewDirectionVertical,
    kCCScrollViewDirectionBoth
} CCScrollViewDirection;

下面来看看这部分的效果：

2. 现在来实现列表展示(ListView)的效果
（1）创建ListViewLayer.h

#ifndef LISTVIEW_LAYER_H
#define LISTVIEW_LAYER_H

#include "cocos2d.h"
#include "cocos-ext.h"

class ListViewLayer : public cocos2d::CCLayer, public cocos2d::extension::CCTableViewDataSource, public cocos2d::extension::CCTableViewDelegate
{
public:
    virtual bool init();  

    virtual void scrollViewDidScroll(cocos2d::extension::CCScrollView* view);

    virtual void scrollViewDidZoom(cocos2d::extension::CCScrollView* view);

    //处理触摸事件，可以计算点击的是哪一个子项
    virtual void tableCellTouched(cocos2d::extension::CCTableView* table, cocos2d::extension::CCTableViewCell* cell);
    //每一项的宽度和高度
    virtual cocos2d::CCSize cellSizeForTable(cocos2d::extension::CCTableView *table);
    //生成列表每一项的内容
    virtual cocos2d::extension::CCTableViewCell* tableCellAtIndex(cocos2d::extension::CCTableView *table, unsigned int idx);
    //一共多少项
    virtual unsigned int numberOfCellsInTableView(cocos2d::extension::CCTableView *table);

    CREATE_FUNC(ListViewLayer);
};

#endif

ListViewLayer继承了CCTableViewDataSource和CCTableViewDelegate。这两个抽象类封装了几个有用的函数，我们在下面的源码中将实现它们。
（2）源文件 ListViewLayer.cpp

#include "ListViewLayer.h"

USING_NS_CC;
USING_NS_CC_EXT;

bool ListViewLayer::init()
{
    bool bRet = false;
    do
    {
        CC_BREAK_IF( !CCLayer::init() );

        CCTableView* pTableView = CCTableView::create(this, CCSizeMake(, ));
        pTableView->setDirection(kCCScrollViewDirectionVertical);
        pTableView->setPosition(CCPointZero);
        pTableView->setDelegate(this);
        pTableView->setVerticalFillOrder(kCCTableViewFillTopDown);
        this->addChild(pTableView);
        pTableView->reloadData();

        bRet = true;
    }while();

    return bRet;
}

void ListViewLayer::tableCellTouched(CCTableView* table, CCTableViewCell* cell)
{
    CCLog("cell touched at index: %i", cell->getIdx());
}

CCSize ListViewLayer::cellSizeForTable(CCTableView *table)
{
    return CCSizeMake(, );
}

CCTableViewCell* ListViewLayer::tableCellAtIndex(CCTableView *table, unsigned int idx)
{
    CCString *pString = CCString::createWithFormat("%d", idx);
    CCTableViewCell *pCell = table->dequeueCell();
    if (!pCell) {
        pCell = new CCTableViewCell();
        pCell->autorelease();
        CCSprite *pSprite = CCSprite::create("listitem.png");
        pSprite->setAnchorPoint(CCPointZero);
        pSprite->setPosition(CCPointZero);
        pCell->addChild(pSprite);

        CCLabelTTF *pLabel = CCLabelTTF::create(pString->getCString(), "Arial", 20.0);
        pLabel->setPosition(CCPointZero);
        pLabel->setAnchorPoint(CCPointZero);
        pLabel->setTag();
        pCell->addChild(pLabel);
    }
    else
    {
        CCLabelTTF *pLabel = (CCLabelTTF*)pCell->getChildByTag();
        pLabel->setString(pString->getCString());
    }

    return pCell;
}

unsigned int ListViewLayer::numberOfCellsInTableView(CCTableView *table)
{
    return ;
}

void ListViewLayer::scrollViewDidScroll(CCScrollView *view)
{
}

void ListViewLayer::scrollViewDidZoom(CCScrollView *view)
{
}

首先需要创建CCTableView，设置它的显示区域和显示方向，这里使用了纵向。设置每个子项的宽度和高度，子项的数量以及每个子项对应的内容。每个子项是一个CCTableViewCell，这里进行了优化，复用了子项对象。
下面是效果图：