有时候场景中的资源加载过多的话就会引起游戏进入的时候很卡，因为那是边加载边显示。在tests例子里面有一个很好的例子叫做TextureCacheTest，里面讲解了如何写loading。
#include "LoadingScene.h"
#include "HelloWorldScene.h"
bool LoadingScene::init()
{
totalNum=9; //记录总的加载数量
haveLoadedNum=0;//记录已加载的数量
this->loading();
return true;
}
CCScene *LoadingScene::scene()
{
CCScene *scene=CCScene::create();
LoadingScene *layer=LoadingScene::create();
scene->addChild(layer);
return scene;
}
void LoadingScene::loading()
{
CCSize size=CCDirector::sharedDirector()->getWinSize();
ttf=CCLabelTTF::create("%0", "Arial", 12);//显示加载进度
CCLabelTTF *havettf=CCLabelTTF::create("Loading", "Arial", 12);
this->addChild(ttf,1);
this->addChild(havettf,1);
ttf->setPosition(ccp(size.width/3, size.height/2));
havettf->setPosition(ccp(size.width/2, size.height/2));
CCTextureCache::sharedTextureCache()->addImageAsync("youlost.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("youwin.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("cat.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catBody1.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catBody2-4.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catBody3.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catHand1.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catHand2.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catTail.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
}
void LoadingScene::loadedCallBack()
{
haveLoadedNum++;
this->runAction(CCDelayTime::create(15));
char tmp[10];
sprintf(tmp, "%%%d",(int)((float)haveLoadedNum/totalNum*100));
ttf->setString(tmp);//更改加载进度
if (haveLoadedNum==9)
{
this->removeChild(ttf, true);//加载完成后，移除加载进度显示
CCScene *newscne=HelloWorld::scene();
CCDirector::sharedDirector()->replaceScene(newscne); //场景切换
}
}
#include "LoadingScene.h"
#include "HelloWorldScene.h"
bool LoadingScene::init()
{
totalNum=9; //记录总的加载数量
haveLoadedNum=0;//记录已加载的数量
this->loading();
return true;
}
CCScene *LoadingScene::scene()
{
CCScene *scene=CCScene::create();
LoadingScene *layer=LoadingScene::create();
scene->addChild(layer);
return scene;
}
void LoadingScene::loading()
{
CCSize size=CCDirector::sharedDirector()->getWinSize();
ttf=CCLabelTTF::create("%0", "Arial", 12);//显示加载进度
CCLabelTTF *havettf=CCLabelTTF::create("Loading", "Arial", 12);
this->addChild(ttf,1);
this->addChild(havettf,1);
ttf->setPosition(ccp(size.width/3, size.height/2));
havettf->setPosition(ccp(size.width/2, size.height/2));
CCTextureCache::sharedTextureCache()->addImageAsync("youlost.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("youwin.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("cat.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catBody1.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catBody2-4.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catBody3.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catHand1.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catHand2.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
CCTextureCache::sharedTextureCache()->addImageAsync("catTail.png", this, callfuncO_selector(LoadingScene::loadedCallBack));
}
void LoadingScene::loadedCallBack()
{
haveLoadedNum++;
this->runAction(CCDelayTime::create(15));
char tmp[10];
sprintf(tmp, "%%%d",(int)((float)haveLoadedNum/totalNum*100));
ttf->setString(tmp);//更改加载进度
if (haveLoadedNum==9)
{
this->removeChild(ttf, true);//加载完成后，移除加载进度显示
CCScene *newscne=HelloWorld::scene();
CCDirector::sharedDirector()->replaceScene(newscne); //场景切换
}
}
这样，在HelloWorld中，就可以通过
bool HelloWorld::init()
{
if ( !CCLayer::init() )
{
return false;
}
CCSprite *sp=CCSprite::createWithTexture(CCTextureCache::sharedTextureCache()->textureForKey("youlost.png"));
addChild(sp,1);
}
bool HelloWorld::init()
{
if ( !CCLayer::init() )
{
return false;
}
CCSprite *sp=CCSprite::createWithTexture(CCTextureCache::sharedTextureCache()->textureForKey("youlost.png"));
addChild(sp,1);
}来获得预加载的图片，从而缓解游戏初步加载时的卡现象。
