cocos2dx tolua传递参数分析

cocos2dx tolua传递参数分析：
tolua_Cocos2d_CCNode_addChild00  == void CCNode::addChild(CCNode *child)
tolua_Cocos2d_CCNode_addChild01  == void CCNode::addChild(CCNode *child, int zOrder)
tolua_Cocos2d_CCNode_addChild02  == void CCNode::addChild(CCNode *child, int zOrder, int tag)

上面是使用tolua把C++转到lua。上面三个分别相应不同的參数个数。

我们这里分析一下最后一个：
/* method: addChild of class  CCNode */
#ifndef TOLUA_DISABLE_tolua_Cocos2d_CCNode_addChild02
static int tolua_Cocos2d_CCNode_addChild02(lua_State* tolua_S)
{
 tolua_Error tolua_err;
 //这里推断參数是否合法，仅仅能推断參数类型是否合法。假设參数类型检查不通过，就会报错
 if (
     !tolua_isusertype(tolua_S,1,"CCNode",0,&tolua_err) ||
     !tolua_isusertype(tolua_S,2,"CCNode",0,&tolua_err) ||
     !tolua_isnumber(tolua_S,3,0,&tolua_err) ||
     !tolua_isnumber(tolua_S,4,0,&tolua_err) ||
     !tolua_isnoobj(tolua_S,5,&tolua_err)
 )
  goto tolua_lerror;
 else
 {
  //比如：middleBg:addChild(testSprite, Z_ORDER_1, 200)
  //我们传递进来的參数和以下的一一相应
  //这里能够清楚的看到传入參数的次序，第一是middleBg ...
  CCNode* self = (CCNode*)  tolua_tousertype(tolua_S,1,0);    --  middleBg   -- 1
  CCNode* child = ((CCNode*)  tolua_tousertype(tolua_S,2,0)); --  testSprite -- 2
  int zOrder = ((int)  tolua_tonumber(tolua_S,3,0));          --  Z_ORDER_1  -- 3
  int tag = ((int)  tolua_tonumber(tolua_S,4,0));             --  200        -- 4
#ifndef TOLUA_RELEASE
  if (!self) tolua_error(tolua_S,"invalid 'self' in function 'addChild'", NULL);
#endif
  {
   //这里就把testSprite加到了middleBg
   self->addChild(child,zOrder,tag);
  }
 }
 return 0;
tolua_lerror:
 return tolua_Cocos2d_CCNode_addChild01(tolua_S);
}
#endif //#ifndef TOLUA_DISABLE

样例：
//middleBg:addChild(testSprite, Z_ORDER_1, 200) 在传递參数中，我们没有对Z_ORDER_1赋值，即为nil，则就
//出现了以下的错误。看下这里argument #3 ，表明是第三个參数错误，而这里我们明明是第二个參数。看下上面的分析
//我想大家应该明确了。通过这样的方法，我们以后查找这类问题。就会方便非常多。

03-31 10:09:50.499: D/cocos2d-x debug info(3169): LUA ERROR: [string "xxxxxxxxxxxxx..."]:171: error in function 'addChild'.
03-31 10:09:50.499: D/cocos2d-x debug info(3169):      argument #3 is 'nil'; '[no object]' expected.
03-31 10:09:50.499: D/cocos2d-x debug info(3169): stack traceback:
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[C]: in function 'addChild'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx..."]:171: in function 'initMiddle'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx..."]:35: in function 'initUI'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx..."]:27: in function 'ctor'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx"]:34: in function 'create'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx"]:38: in function 'new'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx"]:44: in function 'pushScene'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx"]:309: in function 'callBack'
03-31 10:09:50.499: D/cocos2d-x debug info(3169): 	[string "xxxxxxxxxxxxx"]:653: in function <[string "xxxxxxxxxxxxx"]:651>

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