本例子实现了 Flex tree 节点的展开与收缩 , 可以展开所有节点，展开第一层节点，展开名为child5的节点，收缩所有节点-expand the tree of flex , shrink the tree of flex

不错的多点触摸桌小应用，含图片及源代码,里面有多点互动的具体实现方法，很适合新手学习。-Good multi-touch tables small applications, including images and source code, which a number of specific implementation point of interaction, it is suitable for beginners to learn.