cocos2d-x ScrollView、TableView

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

在游戲和應用中經常要實現左右滑動展示游戲幫助、以列表顯示內容的UI效果，就像android中的Gallery和ListView。本文通過CCScrollView和CCTableView分別來實現這兩個效果，基於cocos2d-x 2.0.4版本。
首先來簡單了解一下這兩個東東，CCScrollView本身是一個CCLayer，而CCTableView是CCScrollView的子類，這是引擎已經幫我們封裝好了的，CCTableView可以設置成橫向和縱向，用它可以實現類似於Gallery和ListView的效果。
1. 首先實現游戲幫助界面
(1) 創建頭文件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滾動的時候會調用
    void scrollViewDidScroll(CCScrollView* view);
    //scrollview縮放的時候會調用
    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:
    //根據手勢滑動的距離和方向滾動圖層
     void adjustScrollView(float offset);
     CCScrollView *m_pScrollView;
     CCPoint m_touchPoint;
     int m_nCurPage;
};
 
#endif

類GalleryLayer繼承了CCScrollViewDelegate，實現了它的兩個純虛函數，主要是為了當scrollview滾動和縮放時回調這兩函數，這樣我們就可以在這兩函數中做相關操作了。

(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 = 1;
       CCSize visibleSize = CCDirector::sharedDirector()->getVisibleSize();
       CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();
 
       CCLayer *pLayer = CCLayer::create();
       char helpstr[30] = {0};
       for (int i = 1; i <= 3; ++ i)
       {
           memset(helpstr, 0, sizeof(helpstr));
           sprintf(helpstr,"bg_%02d.png",i);
           CCSprite *pSprite = CCSprite::create(helpstr);
           pSprite->setPosition(ccp(visibleSize.width * (i-0.5f), visibleSize.height / 2));
           pLayer->addChild(pSprite);
       }
 
       m_pScrollView = CCScrollView::create(CCSizeMake(960, 640), pLayer);
       m_pScrollView->setContentOffset(CCPointZero);
       m_pScrollView->setTouchEnabled(false);
       m_pScrollView->setDelegate(this);
       m_pScrollView->setDirection(kCCScrollViewDirectionHorizontal);
       pLayer->setContentSize(CCSizeMake(960*3, 640));
 
       this->addChild(m_pScrollView);
 
       CCSpriteFrameCache *pCache =  CCSpriteFrameCache::sharedSpriteFrameCache();
 
       pCache->addSpriteFrame(CCSpriteFrame::create("button_normal.png",CCRectMake(0, 0, 64, 64)),"button_normal.png");
       pCache->addSpriteFrame(CCSpriteFrame::create("button_selected.png",CCRectMake(0, 0, 64, 64)),"button_selected.png");
       for (int i = 1; i <= 3; ++ i)
       {
           CCSprite *pPoint = CCSprite::createWithSpriteFrameName("button_normal.png");
           pPoint->setTag(i);
           pPoint->setPosition(ccp( origin.x + (visibleSize.width - 3 * pPoint->getContentSize().width)/2 + pPoint->getContentSize().width * (i-1), origin.y + 30));
           this->addChild(pPoint);
       }
        CCSprite *pPoint = (CCSprite *)this->getChildByTag(1);
        pPoint->setDisplayFrame(pCache->spriteFrameByName("button_selected.png"));
 
        bRet = true;
    }while(0);
 
    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, 1, 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) > 50)
    {
        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) > 50)
    {
        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<0)
    {
        m_nCurPage ++;
    }else
    {
        m_nCurPage --;
    }
 
    if (m_nCurPage <1)
    {
        m_nCurPage = 1;
    }
 
    if(m_nCurPage > 3)
    {
        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-1), 0);
        m_pScrollView->setContentOffset(adjustPos, true);
    }
}

這里一共有三張圖，是從捕魚達人中拿出來的背景圖，當滾完三張圖時就跳轉到ListViewLayer場景去，上面的代碼比較容易懂。
首先創建一個CCLayer，包含三張背景圖，設置CCLayer的ContentSize，並設置三張圖片的位置
然后設置CCLayer為CCScrollview的內容，並設置CCScrollView的顯示區域。
最后根據用戶滑動的方向和距離，通過設置scrollview的setContentOffset，滾動視圖。
CCScrollview.h文件中封裝了一個枚舉類型，一共有四個方向，常用橫向和縱向，這里使用了橫向。

typedef enum {
    kCCScrollViewDirectionNone = -1,
    kCCScrollViewDirectionHorizontal = 0,
    kCCScrollViewDirectionVertical,
    kCCScrollViewDirectionBoth
} CCScrollViewDirection;

下面來看看這部分的效果：

 

2. 現在來實現列表展示(ListView)的效果
（1）創建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);
 
    //處理觸摸事件，可以計算點擊的是哪一個子項
    virtual void tableCellTouched(cocos2d::extension::CCTableView* table, cocos2d::extension::CCTableViewCell* cell);
    //每一項的寬度和高度
    virtual cocos2d::CCSize cellSizeForTable(cocos2d::extension::CCTableView *table);
    //生成列表每一項的內容
    virtual cocos2d::extension::CCTableViewCell* tableCellAtIndex(cocos2d::extension::CCTableView *table, unsigned int idx);
    //一共多少項
    virtual unsigned int numberOfCellsInTableView(cocos2d::extension::CCTableView *table);
 
    CREATE_FUNC(ListViewLayer);
};
 
#endif

ListViewLayer繼承了CCTableViewDataSource和CCTableViewDelegate。這兩個抽象類封裝了幾個有用的函數，我們在下面的源碼中將實現它們。
（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(960, 640));
        pTableView->setDirection(kCCScrollViewDirectionVertical);
        pTableView->setPosition(CCPointZero);
        pTableView->setDelegate(this);
        pTableView->setVerticalFillOrder(kCCTableViewFillTopDown);
        this->addChild(pTableView);
        pTableView->reloadData();
 
        bRet = true;
    }while(0);
 
    return bRet;
}
 
void ListViewLayer::tableCellTouched(CCTableView* table, CCTableViewCell* cell)
{
    CCLog("cell touched at index: %i", cell->getIdx());
}
 
CCSize ListViewLayer::cellSizeForTable(CCTableView *table)
{
    return CCSizeMake(960, 120);
}
 
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(123);
        pCell->addChild(pLabel);
    }
    else
    {
        CCLabelTTF *pLabel = (CCLabelTTF*)pCell->getChildByTag(123);
        pLabel->setString(pString->getCString());
    }
 
    return pCell;
}
 
unsigned int ListViewLayer::numberOfCellsInTableView(CCTableView *table)
{
    return 20;
}
 
void ListViewLayer::scrollViewDidScroll(CCScrollView *view)
{
}
 
void ListViewLayer::scrollViewDidZoom(CCScrollView *view)
{
}

首先需要創建CCTableView，設置它的顯示區域和顯示方向，這里使用了縱向。設置每個子項的寬度和高度，子項的數量以及每個子項對應的內容。每個子項是一個CCTableViewCell，這里進行了優化，復用了子項對象。
下面是效果圖：