（1）将*.pvr.ccz文件转换为CCSpriteBatchNode
(2) 将对应的plist文件读到CCSpriteFrameCache中
(3) 从CCSpriteFrameCache获取资源文件
CCSpriteBatchNode *backgoundBgNode = [CCSpriteBatchNode batchNodeWithFile:@"background.pvr.ccz"];
[self addChild:backgoundBgNode]; [[CCSpriteFrameCache sharedSpriteFrameCache]addSpriteFramesWithFile:@"background.plist"]; CCSprite *background = [CCSprite spriteWithSpriteFrameName:@"MuleDeer-ipadhd.png"];
background.anchorPoint = ccp(0, 0);
[backgoundBgNode addChild:background];