flex tree拖动

//moveTree.mxml文件

<?xml version="1.0" encoding="utf-8"?>  
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" fontSize="15" 
    xmlns:comp="com.components.moveTree.*" xmlns:component="com.component.*">  
 <mx:Script>  
  <![CDATA[  
   import mx.events.DragEvent;  
   import mx.managers.DragManager;  
   import mx.core.DragSource;  
   import mx.events.DragEvent;  
   private function dropDrag(event:DragEvent):void {  
    tree.hideDropFeedback(event); //取消默认画线  
   }  
  ]]>  
 </mx:Script>  
 <mx:XMLListCollection id="xmlColl" source="{xmlList}"/>  
 <mx:XMLList id="xmlList" xmlns="">  
  <rootdata name="北京XX总局"  position="教授" isBranch="true"> 
   <subdata   name="大队1"  isBranch="true" >  
   <data  name="中队1-1"/>
   <data  name="中队1-2"/>
   <data  name="中队1-3"/>
   </subdata>
   <subdata   name="大队2"  isBranch="true" >  
    <data  name="中队2-1"/>
   </subdata>
  </rootdata>
  <rootdata name="信息分类" isBranch="true">  
   <subdata id="01" name="Flash" isBranch="true">  
    <data id="0101" name="Flash1" />  
    <data id="0102" name="Flash2" />  
   </subdata>  
   <subdata id="01" name="相册" isBranch="true">  
    <data id="0104" name="相册1" />  
    <data id="0104" name="相册2" />  
   </subdata>  
   <subdata id="02" name="服务" isBranch="true">  
    <data id="0201" name="GIS服务" />  
    <data id="0202" name="arcgis服务" />  
   </subdata>  
    
  </rootdata>  
 </mx:XMLList> 
 <mx:HBox horizontalAlign="center" verticalAlign="middle" paddingLeft="15" paddingRight="15" dropShadowVisible="true" height="90%" width="100%">
  
 
 <mx:HBox width="100%" height="100%" horizontalAlign="left" verticalAlign="middle">
  

 <mx:Panel width="250" height="100%" verticalAlign="middle" horizontalAlign="center" title="结构" chromeColor="#020202" color="#FFFFFF">
  
 
  <component:moveTree
  id="tree" labelField="@name" width="100%" 
  disclosureOpenIcon="@Embed(source='img/disclosure-open.png')"
  disclosureClosedIcon="@Embed(source='img/disclosure-closed.png')"
      height="100%" dragEnabled="true" dropEnabled="true" 
      dragMoveEnabled="true" dragDrop="dropDrag(event);" dataProvider="{xmlColl}" dropShadowVisible="true" borderVisible="false" color="#010101"/> 
 </mx:Panel>
 </mx:HBox>
 </mx:HBox>
</mx:Application> 
 

 

//moveTree.as

package com.component
{
 import mx.collections.ICollectionView;  
 import mx.collections.IViewCursor;  
 import mx.controls.Tree;  
 import mx.core.mx_internal;  
 import mx.events.DragEvent;  
 
 import mx.managers.DragManager;  
  use namespace mx_internal; //命名空间  
 
 public class moveTree extends Tree {  
  
  public function moveTree() {  
   super();  
  }  
  /** 
   *  @private 
   *  Returns the stack of parents from a child item. 
   */ 
  private function getParentStack(item:Object):Array {  
   var stack:Array = [];  
   if (item == null)  
    return stack;  
   
   var parent:* = getParentItem(item);  
   while (parent) {  
    stack.push(parent);  
    parent = getParentItem(parent);  
   }  
   return stack;  
  }  
  override protected function dragDropHandler(event:DragEvent):void {  
   
   if (event.dragSource.hasFormat("treeItems")) {  
    var items:Array = event.dragSource.dataForFormat("treeItems") as Array;  
    var i:int;  
    var n:int;  
    
    if (event.action == DragManager.MOVE && dragMoveEnabled) {  
     if (event.dragInitiator == this) {  
       calculateDropIndex(event);  
    
      var index:int;  
      var parent:*;  
      var parentItem:*;  
      
      var dropIndex:int = _dropData.index;  
      
      // 获得 拖动目标 项的父节点  。  
      var dropParentStack:Array = getParentStack(_dropData.parent);  
      dropParentStack.unshift(_dropData.parent); //将父节点添加到数组的开头  
      n = items.length;  
      for (i = 0;i < n;i++) {  
       parent = getParentItem(items[i]); //获得父节点  
       index = getChildIndexInParent(parent,items[i]); //获得父节点的索引号  
       
       var item:* = items[i];  
       var itemName:String = item.localName().toString(); //  
       var targetParent:*;  
       if(itemName == "rootdata"){
    
       removeChildItem(parent,items[i],index);  

       if (parent == _dropData.parent && index < _dropData.index)  
        dropIndex--;  
       
       addChildItem(targetParent,items[i],dropIndex);  
                  
             }
       for each (parentItem in dropParentStack) {  
    
        // 不能把节点放到自身的子节点下面  
        if (items[i] === parentItem)  
         return;  
        
        if (parentItem) {  
         var targetParentName:String = parentItem.localName().toString();  
         if (itemName == "data" && targetParentName == "subdata") {  
          targetParent = parentItem;  
          break;  
         }  
         if (itemName == "subdata" && targetParentName == "rootdata") {  
          targetParent = parentItem;  
          break;  
         }  
        }  
        
       }  
       
       if (targetParent) { 
        removeChildItem(parent,items[i],index);  
    
        if (parent == _dropData.parent && index < _dropData.index)  
         dropIndex--;  
        
        addChildItem(targetParent,items[i],dropIndex);  
       }  
      }  
      
      return;  
     }  
    }  
    
 
    lastDragEvent = null;  
   }  
  }  
  /** 
   *  @private 
   *  Finds the index distance between a parent and child 
   */ 
  private function getChildIndexInParent(parent:Object,child:Object):int {  
   var index:int = 0;  
   if (!parent) {  
    var cursor:IViewCursor = ICollectionView(iterator.view).createCursor();  
    while (!cursor.afterLast) {  
     if (child === cursor.current)  
      break;  
     index++;  
     cursor.moveNext();  
    }  
   } else {  
    if (parent != null && _dataDescriptor.isBranch(parent,iterator.view) && _dataDescriptor.hasChildren(parent,  
     iterator.view)) {  
     var children:ICollectionView = getChildren(parent,iterator.view);  
     if (children.contains(child)) {  
      cursor = children.createCursor();  
      while (!cursor.afterLast) {  
       if (child === cursor.current)  
        break;  
       cursor.moveNext();  
       index++;  
      }  
      
     } else {  
        
     }  
    }  
   }  
   return index;  
  }  
 }  
}