flex下的树形下拉框treecombobox

不多说了，组件代码如下：

1. <?xml version="1.0" encoding="utf-8"?>
2. <mx:ComboBox  xmlns:mx="http://www.adobe.com/2006/mxml" creationComplete="initComponent()">
3. <mx:Script>
4.     <![CDATA[
5.            import mx.events.FlexEvent; 
6.            [Bindable] 
7.            private var _label:String; 
8.            [Bindable] 
9.            public var treeSelectedItem:Object;
11.            public function initComponent():void
12.            {
13.             
14.            }
15.                         
16.            public function updateLabel(event:*):void{  
17.                     _label = event.currentTarget.selectedItem[this.labelField];     
18.                     treeSelectedItem = event.currentTarget.selectedItem; 
19.            } 
20.            
21.            override protected function updateDisplayList(unscaledWidth:Number,
22.                                                   unscaledHeight:Number):void
23.             {
24.                 super.updateDisplayList(unscaledWidth, unscaledHeight);  
25.                 
26.                 if(dropdown && _label != null){   
27.                     text = _label; 
28.                 } 
29.             }
31.              
32.     ]]>
33. </mx:Script>
34.     <mx:dropdownFactory>
35.       <mx:Component> 
36.         <mx:Tree creationComplete="initTree()" change="outerDocument.updateLabel(event)" showRoot="true" height="500" width="500">
37.          <mx:Script>
38.                 <![CDATA[
39.                 public function initTree():void {
40.                     var len:int=super.dataProvider.length;
41.                     for(var i:int;i<len;i++)
42.                     {
43.                         super.expandChildrenOf(super.dataProvider[i], true);
44.                     }
45.                     super.selectedItem=outerDocument.treeSelectedItem;
46.                 }
47.                 ]]>
48.             </mx:Script>
49.         </mx:Tree>
50.      </mx:Component>
51.     </mx:dropdownFactory>
52. </mx:ComboBox>

调用的app代码如下：

1. <?xml version="1.0" encoding="utf-8"?>
2. <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns:ns1="components.*">
3.     <ns1:ComboTree  width="300" id="combo" labelField="@label" >
4.         <mx:XMLListCollection id="MailBox">
5.             <mx:XMLList>
6.                 <folder label="Mail">
7.                  <folder label="INBOX"/>
8.                  <folder label="Personal Folder">
9.                     <Pfolder label="Business" />
10.                      <Pfolder label="Demo" /> 
11.                          <Pfolder label="Personal" isBranch="true" /> 
12.                          <Pfolder label="Saved Mail" /> 
13.                     </folder>
14.                     <folder label="Sent" />
15.                     <folder label="Trash" />
16.                 </folder>
17.                 <folder label="Mail2">
18.                  <folder label="INBOX2"/>
19.                  <folder label="Personal Folder2">
20.                     <Pfolder label="Business2" />
21.                      <Pfolder label="Demo2" /> 
22.                          <Pfolder label="Personal2" isBranch="true" /> 
23.                          <Pfolder label="Saved Mail2" /> 
24.                     </folder>
25.                     <folder label="Sent2" />
26.                     <folder label="Trash2" />
27.                 </folder>
28.             </mx:XMLList>
29.         </mx:XMLListCollection>
30.     </ns1:ComboTree>
31. </mx:Application>