cocos2d CCScrollView 解析

CCNode 重要属性：

m_obAnchorPoint = CCPointZero  
m_obPosition = CCPointZero 

#"whole screen objects. like Scenes and Layers,should set m_bIgnoreAnchorPointForPosition to true"

m_bIgnoreAnchorPointForPosition = false
m_obContentSize = CCSizeZero

cclayer 和 CCScene 继承与 CCNode
并更改了上述部分属性：

**cclayer:**
 m_bIgnoreAnchorPointForPosition = true
 setAnchorPoint = ccp(0.5,0.5)
 m_obContentSize = winSize

#cclayer加入了对外部事件的处理如触摸，重力，菜单按钮。
#默认cclayer不处理外部事件
 m_bTouchEnabled(false),m_bAccelerometerEnabled(false),m_bKeypadEnabled(false),##CCScene:##
 m_bIgnoreAnchorPointForPosition = true
 setAnchorPoint = ccp(0.5,0.5)
 m_obContentSize = winSize

CCScrollView 继承自 cclayer ，则继承下来的属性又 锚点为m_obAnchorPoint = ccp(0.5 0.5) 并且ignoreAnchorPointForPosition = true