Actionscript 3 addChild問題

Question

這是一個xml圖像菜單的測試。在我創建我的容器的代碼中，我在舞臺（menu_mc）中有一個影片剪輯。

CODE：

import flash.display.MovieClip; 
import fl.text.TLFTextField; 
import flashx.textLayout.formats.TextLayoutFormat; 
import flashx.textLayout.elements.TextFlow; 
import flashx.textLayout.formats.TextAlign; 
import flash.display.Sprite; 

var title_mc:TLFTextField; 
var img_mc:MovieClip; 
var bg_mc:MovieClip; 
var myFormat:TextLayoutFormat; 
var myTextFlow:TextFlow; 

createContainers(); 

function createContainers():void { 

//CREATE IMAGE CONTAINER 
img_mc = new MovieClip(); 
menu_mc.addChild(img_mc); 
img_mc.x = -50; 
img_mc.y = -60,10; 

//CREATE TEXTFIELD 
title_mc = new TLFTextField(); 
addChild(title_mc); 
title_mc.x = 0; 
title_mc.y = 20; 
title_mc.width = 120; 
title_mc.height = 50,70; 
title_mc.multiline = true; 
title_mc.embedFonts = true; 
title_mc.antiAliasType = AntiAliasType.ADVANCED; 
title_mc.wordWrap = true; 
title_mc.text = "text text text text text text text"; 

myFormat = new TextLayoutFormat(); 
myFormat.textIndent = 0; 
myFormat.color = 0x0000FF; 
myFormat.fontFamily = "Arial"; 
myFormat.fontSize = 20; 
myFormat.textAlign = TextAlign.CENTER; 
myFormat.textAlignLast = TextAlign.CENTER; 

myTextFlow = title_mc.textFlow; 
myTextFlow.hostFormat = myFormat; 
myTextFlow.flowComposer.updateAllControllers(); 

//CREATE BACKGROUND CONTAINER 
bg_mc = new MovieClip(); 
menu_mc.addChild(bg_mc); 
bg_mc.x = 0; 
bg_mc.y = 70; 
bg_mc.width = 120; 
bg_mc.height = 50; 

//CRETAE SPRITE 
var square:Sprite = new Sprite(); 
square.graphics.lineStyle(1,0x000000); 
square.graphics.beginFill(0x000000); 
square.graphics.drawRect(0,0,300,300); 
square.graphics.endFill(); 
menu_mc.addChild(square); 

} 

我的問題是我想要的，例如bg_mc內bg_mc它將menu_mc內和方形。

如果我嘗試例如：

menu_mc.bg_mc.addChild(square); //error 

或

menu_mc.addChild(title_mc); //textfield disapears 

閃存給我這個錯誤：

類型錯誤：錯誤＃1010：一個術語是不確定的，沒有屬性

爲什麼？

Answer 1

如果你想bg_mc內menu_mc做：menu_mc.addChild(bg_mc)， 然後裏面bg_mcsquare做：bg_mc.addChild(square)。

menu_mc.bg_mc.addChild(square);會給你一個錯誤，因爲在MovieClipmenu_mc沒有名爲bg_mc的屬性。添加子XYZ並不意味着創建名爲XYZ的屬性。