倒计时颜色渐变动画效果

    CCSize s = CCDirector::sharedDirector()->getWinSize();

    change = 0;

　　//头像
    CCSprite *ava = CCSprite::create("girl.jpg");

　　//默认绿色计时条
    CCProgressTimer *left = CCProgressTimer::create(CCSprite::create("b5s.png"));
    left->setType( kCCProgressTimerTypeRadial );
　　//顺时针
    left->setReverseDirection(true);
　　//进度条百分比
    left->setPercentage(100);
    ava->setPosition(ccp(100, s.height/2));
    di->setPosition(ccp(100, s.height/2));
    addChild(di);
    addChild(ava);
    addChild(left, 0, 200);
    left->setPosition(ccp(100, s.height/2));
　　//增加每秒状态更新函数
    this->schedule(schedule_selector(HelloWorld::update), 1.0);
　　//15秒倒计时，状态条从100变0
    CCProgressFromTo *from = CCProgressFromTo::create(15, 100, 0);
    left->runAction(CCRepeatForever::create(from));

void HelloWorld::update(float dt)
{
    CCProgressTimer *left = ((CCProgressTimer*)this->getChildByTag(200));
    if ((left->getPercentage() > 67) && (left->getPercentage() < 100) && (0 == change))
    {
        left->setSprite(CCSprite::create("b5s.png"));
        change = 1;
    }
    if ((left->getPercentage() > 33) && (left->getPercentage() < 67) && (1 == change))
    {
        left->setSprite(CCSprite::create("m5s.png"));
        change = 2;
    }
    if ((left->getPercentage() > 0) && (left->getPercentage() < 33) && (2 == change))
    {
        left->setSprite(CCSprite::create("a5s.png"));
        change = 0;
    }

    if(left->getPercentage() == 0)
    {
        left->setPercentage(100);
        change = 0;
    }
}