(Flex SDK4)关于BorderContainer 的addChild/addElement 问题

flex中 addChild添加不能用

addChild只能添加UI组件，所以Sprite不能添加。

解决方法：

方法1.　　var mySprite:Sprite = new Sprite();       
    mySprite.x=0;
    mySprite.y=0;
    mySprite.graphics.beginFill(0xFFCC00);
    mySprite.graphics.drawCircle( 40, 40, 40 );

　var ui:UIComponent=new UIComponent();//创建一个组件，把
    ui.addChild(mySprite);
    bc.addChild(ui);

方法2：

　　 bc.rawChildren.addChild(ui);

flex 4中，addChild 总是不能显示。

解决：

The following table shows these properties and methods:

Spark container	MX container	Description
numElements	numChildren	Number of children the container.
addElement()	addChild()	Adds a child to the container as the last child.
addElementAt()	addChildAt()	Add a child at a specific index in the container.
	getChildren()	Returns an Array containing all children.
getElementAt()	getChildAt()	Return a child at the specified index.
	getChildByName()	Return a child with the specified id.
getElementIndex()		Returns the index of a child.
removeAllElements()	removeAllChildren()	Removes all container children.
removeElement()	removeChild()	Remove the first child.
removeElementAt()	removeChildAt()	Remove the child at the specified index
setElementIndex()	setChildIndex()	Set the index of a child.
swapElements()	swapChildren()	Swap the indexes of two children
swapElementsAt()	swapChildrenAt()	Swap the indexes of two children.

Spark用addElement,MX用addChild

xmlns:s="library://ns.adobe.com/flex/spark"

xmlns:mx="library://ns.adobe.com/flex/mx"

应该就是这个来区分MX还是Spark吧

源文：http://help.adobe.com/en_US/flex/using/WS2db454920e96a9e51e63e3d11c0bf62b90-7fe9.html