Flex 中树的多种操作(可编辑，拖拽，新增删除等操作)

<?xml version="1.0" encoding="utf-8"?>
<mx:Canvas xmlns:fx="http://ns.adobe.com/mxml/2009" 
  xmlns:s="library://ns.adobe.com/flex/spark" 
  xmlns:mx="library://ns.adobe.com/flex/mx" width="400" height="300" creationComplete="init();">
<fx:Declarations>
<!-- 将非可视元素（例如服务、值对象）放在此处 -->
<mx:XMLListCollection id="datatree" source="{_xmldata.children()}" />
</fx:Declarations>


<fx:Script>
<![CDATA[
import mx.controls.treeClasses.TreeItemRenderer;
import mx.controls.listClasses.ListItemRenderer;
import mx.events.ItemClickEvent;
import mx.states.AddChild;
import mx.controls.Alert;
import flash.events.MouseEvent;

import mx.controls.listClasses.IListItemRenderer;

private var xml:XML;
private var MNum:int = 8;
private var ANum:int = 0;
[Bindable]
private var _xmldata:XML = 
<stage>
<AllNode id="1" label="总节点1">
 <Node id="2" label="子节点"></Node>
 <Node id="3" label="子节"></Node>
 <Node id="4" label="子"></Node>
 </AllNode>
 <AllNode id="5" label="总节点2">
 <Node id="6" label="子节点2"></Node>
 <Node id="7" label="子节2"></Node>
 <Node id="8" label="子2"></Node>
 </AllNode>
</stage>




private var createMenu: ContextMenuItem;    
private var deleteMenu: ContextMenuItem;    
private var renameMenu: ContextMenuItem;    


internal function init(): void{    
treeMenu();  
xml =  _xmldata;       
tree.addEventListener(ListEvent.ITEM_EDIT_END, itemEditEndHandler); 
tree.addEventListener(ListEvent.ITEM_EDIT_BEGINNING, itemEditBeginHandler); 
}    

private function itemEditBeginHandler(event: ListEvent): void{ 
var targetTree: Tree = Tree(event.target); 
var item:XML = new XML(targetTree.selectedItem);   
if(item.@editabled == "false"){ 
event.preventDefault(); 
} 
}


private function itemEditEndHandler(event:ListEvent):void
{
tree.editable = false;
}

//用event.currentTarget.itemEditorInstance.text得到编辑后的内容

//这个方法在那个是不成功，自己重写了一个
/*   
public function itemEditEndHandler(event:ListEvent):void { 
event.preventDefault(); 
var newValue:String = event.currentTarget.itemEditorInstance.text; 
trace("newValue:"+newValue); 

tree.editedItemRenderer.data.@name = newValue; 
tree.destroyItemEditor(); 
}  
*/

private function treeMenu(): void{    
createTreeMenuItem();    
tree.contextMenu = getTreeContxtMenu();    
}    

public function createTreeMenuItem(): void{    
createMenu = new ContextMenuItem("新建"); 
deleteMenu = new ContextMenuItem("de22");  
renameMenu = new ContextMenuItem("重命名");   
createMenu.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, createNode);    
deleteMenu.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, deleteNode);    
renameMenu.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT, renameNode);    
}    


private function getTreeContxtMenu(): ContextMenu{    
var contextMenu: ContextMenu = new ContextMenu();    
contextMenu.hideBuiltInItems();    
contextMenu.customItems.push(createMenu);   
contextMenu.customItems.push(deleteMenu);   
contextMenu.customItems.push(renameMenu);    
return contextMenu;    
}  


private function createNode(event:ContextMenuEvent):void{

var item:Object = onRightClicked(event);

if (item != null) { 

if( xml == null ) return;

if( xml.length() > 0 )
{

//关闭节点，如果不这样做，会有问题
item = tree.selectedItem;
if (tree.dataDescriptor.isBranch(item) && tree.isItemOpen(item)) {
tree.expandItem(item, false);
}

ANum ++;   
var nodeId: int =  MNum + 1;


//添加新节点
var nodeString:String = "<Node id=\""+nodeId+"\" label=\""+"新节点"+"\" ></Node>";
var _XML:XML = new XML(nodeString);

_XML.@label = "新节点"+ANum;     
(item as XML).appendChild(_XML);


//展开该节点
item = tree.selectedItem;
if (tree.dataDescriptor.isBranch(item) && !tree.isItemOpen(item)) {
tree.expandItem(item, true);
}

//定位到新节点      
var children:XMLList = XMLList(item as XML).children();

for(var i:Number=0; i < children.length(); i++) {                   

if( children[i].@label == _XML.@label ) {                     

var newItemRender:IListItemRenderer;

var newNodeIndex:int;

tree.visible = true;

tree.firstVisibleItem = children[i] as Object;

//这句定位要求，是树中可见的节点中定位
newItemRender = tree.itemToItemRenderer(children[i] as Object);

if(newItemRender != null) {               

newNodeIndex =  tree.itemRendererToIndex(newItemRender);               

if(tree.selectedIndex != newNodeIndex) {  

tree.selectedIndex = newNodeIndex;

tree.editable = true;

tree.editedItemPosition = {rowIndex: tree.selectedIndex};   

} 

}else{
tree.selectedItem = children[i] as Object;

tree.editable = true;

tree.editedItemPosition = {rowIndex: tree.selectedIndex};   
}

//如果不加这几句，有时候就不好使啊！被迫加上了，以后有改进的办法了再说吧                
tree.firstVisibleItem = children[i] as Object;

tree.selectedItem = children[i] as Object;

tree.editable = true;

tree.editedItemPosition = {rowIndex: tree.selectedIndex}; 

break; 
}
}                   
MNum++; 


}
}
else    return;       
}


private function deleteNode(event:ContextMenuEvent):void{

var item:Object = onRightClicked(event);

if (item != null) { 

if( xml == null ) return;

if( xml.length() > 0 )
{
tree.dataDescriptor.removeChildAt(

tree.selectedItem.parent(),

tree.selectedItem,

tree.selectedItem.childIndex(),

tree.dataProvider

);
}
}
else    return;       

}

private function renameNode(event:ContextMenuEvent):void{

var item:Object = onRightClicked(event);

if (item != null) { 

if( xml == null ) return;           
if( xml.length() > 0 )
{
tree.editable = true;
tree.editedItemPosition = {rowIndex: tree.selectedIndex};
}
}
else    return;  
}

//右键定位节点
private function onRightClicked(e:ContextMenuEvent):Object

{

var rightClickItemRender:IListItemRenderer; 

var rightClickIndex:int;

if(e.mouseTarget is IListItemRenderer) {  

rightClickItemRender = IListItemRenderer(e.mouseTarget);  

}else if(e.mouseTarget.parent is IListItemRenderer) {  

rightClickItemRender = IListItemRenderer(e.mouseTarget.parent);  

} 


if(rightClickItemRender != null) {  

rightClickIndex =  tree.itemRendererToIndex(rightClickItemRender);  

if(tree.selectedIndex != rightClickIndex) {  

tree.selectedIndex = rightClickIndex; 

} 
trace("通过右键单击获得选定的行: " + tree.selectedIndex);  

} 

//树节点的xml    
var globalItem:Object = tree.selectedItem; 

if(globalItem != null){

var node:XML = (globalItem as XML)

trace("通过右键单击获得选定的行: " + node.@id +",node.label:"+ node.@label); 


if (node.@id != undefined)

return globalItem; 

else{

Alert.show("此节点不可操作");

return null;

}  
}
return null;

}

import mx.collections.ICollectionView;

import mx.events.ListEvent;


//鉴于单击收缩功能可能影响到右键操作，所以废除了
private function tree_itemClick(evt:ListEvent):void {

var item:Object = Tree(evt.currentTarget).selectedItem;

if (tree.dataDescriptor.isBranch(item)) {

tree.expandItem(item, !tree.isItemOpen(item), true);

}

}

/******变换选中的tree节点事件，透过这个改变xml，该方法必须有********/
private function treeChange(e:Event):void
{
xml = e.currentTarget.selectedItem as XML;
}

private function tree_itemDoubleClick(event: ListEvent):void{

var node:XML = tree.selectedItem as XML; 
var isOpen:Boolean = tree.isItemOpen(node); 
tree.expandItem(node, !isOpen);     
}

private function doubleClickHandler(event:MouseEvent):void
{
tree.editable = true;
tree.editedItemPosition = {rowIndex: tree.selectedIndex};
}

]]>
</fx:Script>

<!-- doubleClickEnabled="true" 
itemDoubleClick="tree_itemDoubleClick(event);" -->


<mx:Tree id="tree" 
width="100%" 
height="100%" 
fontFamily="Arial" 
fontSize="12" 
textAlign="left" 
dataProvider="{datatree}" 
labelField="@label"
change="treeChange(event)" 
rowCount="10"
doubleClickEnabled="true"
doubleClick="doubleClickHandler(event)"
itemEditEnd="itemEditEndHandler(event)"
dragEnabled="true"
dropEnabled="true"
/>

</mx:Canvas>