cocos2d新手问题：加载plist后为何只加载第一帧图片

下面是我的代码：
SpriteFrameCache::getInstance()->addSpriteFramesWithFile("fireman.plist");

auto pSprite1 = Sprite::create("fireman2.png");
pSprite1->setPosition(150, 150);
this->addChild(pSprite1,2);

Vector<SpriteFrame*>list;
list.reserve(7);
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman2.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman3.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman4.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman5.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman6.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman1.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman0.png"));
//创建Animation动画，每帧间隔为0.2s，重复播放
auto pAnimation = Animation::createWithSpriteFrames(list, 0.2f, 100);

auto pAnimate = Animate::create(pAnimation);

pSprite1->runAction(pAnimate);

SpriteFrameCache::getInstance()->addSpriteFramesWithFile("fireman.plist");
auto pSprite1 = Sprite::create("fireman2.png");
pSprite1->setPosition(150, 150);
this->addChild(pSprite1,2);

Vectorlist;
list.reserve(7);
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman2.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman3.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman4.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman5.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman6.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman1.png"));
list.pushBack(SpriteFrameCache::getInstance()->getSpriteFrameByName("fireman0.png"));
//创建Animation动画，每帧间隔为0.2s，重复播放
auto pAnimation = Animation::createWithSpriteFrames(list, 0.2f, 100);

auto pAnimate = Animate::create(pAnimation);

pSprite1->runAction(pAnimate);