找出flex组件(树)是否可滚动?

通过扩展树类找到解决方案:

public class ExtendedTree extends Tree
{
    public function ExtendedTree()
    {
        super();
    }

    public function get isVerticalScrollable():Boolean
    {
        if (super.verticalScrollBar == null || super.verticalScrollBar.visible == false)
            return false;
        return true;
    }
}

使用MaxVerticalScrollPosition和MaxHorizontalScrollPosition属性。