Flex 操作tree 节点的增加删除

在flex里对树节点的增加和删除操作比较简单，本人也是在网上找了一些资源学习了一下，下面就是对树简单操作的代码直接粘到项目就可以看到效果

<?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:VerticalLayout horizontalAlign="center" verticalAlign="middle"/>
	</s:layout>
	<fx:Declarations>
	</fx:Declarations>
	<fx:Script>
		<![CDATA[
			import mx.collections.ArrayCollection;
			[Bindable]
			private var d:XML = XML("<node value = 'test'></node>") ;
			[Bindable]
			private var dgdp:ArrayCollection = new ArrayCollection();
			
			protected function addNode(event:Event):void
			{
				var newNode:XML = <node/>;
				newNode.@value = ti.text;
				var node:XML = XML(tree.selectedItem);
				newNode.children()
				node.appendChild(newNode);
				ti.text = "";
				
			}
			
			protected function delNode():void
			{
				if(tree.selectedIndex == -1){
					return;
				}else{
					var node:XML = XML(tree.selectedItem);
					var child:XMLList = XMLList(node.parent()).children();
					for(var i:int = 0;i < child.length();i++){
						if((child[i].@value == node.@value)&&(node.@isBranch=true)){
							delete child[i];
						}
					}
				}
			}
		]]>
	</fx:Script>
	<mx:Tree id="tree" width="400" height="400" labelField="@value" dataProvider="{d}">
		
	</mx:Tree>
	<s:HGroup width="400" height="40" verticalAlign="middle" paddingLeft="10" >
		<s:TextInput id="ti"/>
		<s:Button label="add" enabled="{ti.text==''?false:true}" click="addNode(event)"/>
		<s:Button label="delete" enabled="{tree.selectedIndex!=-1?true:false}" click="delNode()"/>
	</s:HGroup>
</s:Application>