cocos2d学习（06）——CCNode::addChild(…)在做什么？

   1: void CCNode::addChild(CCNode *child)

   2: {

   3:     CCAssert( child != NULL, "Argument must be non-nil");

   4:     this->addChild(child, child->m_nZOrder, child->m_nTag);

   5: }

   6:  

   7:  

   8: void CCNode::addChild(CCNode *child, int zOrder)

   9: {

  10:     CCAssert( child != NULL, "Argument must be non-nil");

  11:     this->addChild(child, zOrder, child->m_nTag);

  12: }

  13:  

  14:  

  15: void CCNode::addChild(CCNode *child, int zOrder, int tag)

  16: {    

  17:     //判断参数是否合法

  18:     CCAssert( child != NULL, "Argument must be non-nil");

  19:     CCAssert( child->m_pParent == NULL, "child already added. It can't be added again");

  20:  

  21: //    一个节点的父节点指针是CCNode*，其子节点保存在CCArray数组中，其本质也是CCObject

  22: //    CCArray *m_pChildren;               ///< array of children nodes

  23: //    CCNode *m_pParent;                  ///< weak reference to parent node

  24:  

  25:     if( ! m_pChildren )

  26:     {    //子节点数组不存在，申请空间

  27:         this->childrenAlloc();

  28: //        void CCNode::childrenAlloc(void)

  29: //        {

  30: //            m_pChildren = CCArray::createWithCapacity(4);    //create的时候调用了autorelease()

  31: //            m_pChildren->retain();        //引用计数加一，防止被释放掉

  32: //        }

  33:     }

  34:     //插入子节点指针

  35:     this->insertChild(child, zOrder);

  36:  

  37: //    int m_nTag;    ///< a tag. Can be any number you assigned just to identify this node

  38: //                        一个标记，可以是任意一个整数，你应该分配一个合理的值给这个节点

  39:     child->m_nTag = tag;    //设置Child的tag，可以是任意数

  40:  

  41:     child->setParent(this);        //设置父节点为当前调用addChild函数的节点

  42:     child->setOrderOfArrival(s_globalOrderOfArrival++);

  43:  

  44:     if( m_bRunning )

  45:     {

  46:         child->onEnter();

  47:         child->onEnterTransitionDidFinish();

  48:     }

  49: }