全部展开树节点

 

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical">
    <mx:Script>
        <![CDATA[
            private function expandTree(expand:Boolean):void {
                tree.validateNow();
                tree.expandChildrenOf(treeData, expand);
            }
        ]]>
    </mx:Script>
    <mx:XML id="treeData" xmlns="">
        <root label="root">
            <menu label="node1">
                <menu label="node1.1"/>
                <menu label="node1.2"/>
                <menu label="node1.3"/>
            </menu>
            <menu label="node2">
                <menu label="node2.1"/>
                <menu label="node2.2"/>
                <menu label="node2.3"/>
            </menu>
        </root>        
    </mx:XML>
    <mx:Tree id="tree" dataProvider="{treeData}" 
        width="200" height="300"
        labelField="@label"/>
    <mx:Button label="全部展开" click="expandTree(true)"/>
    <mx:Button label="全部收起" click="expandTree(false)"/>
</mx:Application>