Flex tree

  flex tree例子

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
   xmlns:s="library://ns.adobe.com/flex/spark"
   xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">
<s:layout>
<s:BasicLayout/>
</s:layout>
<fx:Declarations>
<!-- 将非可视元素（例如服务、值对象）放在此处 -->
</fx:Declarations>
<fx:Script>
<![CDATA[
import mx.collections.XMLListCollection;

[Bindable]
private var company:XML =
<list>
  <department title="Finance" code="200">
  <employee name="John H"/>
  <employee name="Sam K"/>
  </department>
  <department title="Operations" code="400">
 
  </department>                  
  <department title="Engineering" code="300">
  <employee name="Erin M"/>
  <employee name="Ann B"/>
  </department>                              
</list>;

[Bindable]
private var companyData:XMLListCollection = new XMLListCollection(company.department);

private function treeLabel(item:Object):String
{
var node:XML = XML(item);
if( node.localName() == "department" )
return node.@title;
//Alert.s
else
return node.@name;
}
private function addEmployee():void
{
var newNode:XML = <employee/>;
newNode.@name = empName.text;
var dept:XMLList =company.department.(@title == "Operations");
if( dept.length() > 0 ) {
dept[0].appendChild(newNode);
empName.text = "";
}
}
private function removeEmployee():void
{
var node:XML = XML(tree.selectedItem);
if( node == null ) return;
if( node.localName() != "employee" ) return;

var children:XMLList = XMLList(node.parent()).children();
for(var i:Number=0; i < children.length(); i++) {
if( children[i].@name == node.@name ) {
delete children[i];
}
}
}

private function itemClick():void{
   
}
]]>
</fx:Script>

<mx:Tree id="tree" top="72" left="50" dataProvider="{companyData}"
labelFunction="treeLabel"
height="224" width="179" click=""/>
<mx:HBox>      
<mx:Button label="Add Operations Employee" click="addEmployee()"/><mx:TextInput id="empName"/>
</mx:HBox>
<mx:Button label="Remove Selected Employee" click="removeEmployee()" x="194" y="43"/>  
</s:Application>

  一个好的参考文章：《Flex3入门教程：Tree控件是一个枝和叶结点分层次的机构》