Flex 改变树结点图标的2种方法介绍

@namespace s "library://ns.adobe.com/flex/spark";
@namespace mx "library://ns.adobe.com/flex/mx";
mx|Tree{
/*去掉默认文件夹图标*/
folderClosedIcon: Embed(source='resource/region.png-600');
folderOpenIcon: Embed(source='resource/region.png-600');
/*去掉叶子节点图标
defaultLeafIcon: ClassReference(null);
*/
/*
defaultLeafIcon 指定叶图标
disclosureClosedIcon 指定的图标旁边显示一个封闭的分支节点。默认的图标是一个黑色三角形。
disclosureOpenIcon 指定的图标旁边显示一个开放的分支节点。默认的图标是一个黑色三角形。
folderClosedIcon 关闭指定的文件夹图标的一个分支节点。
folderOpenIcon 指定打开的文件夹图标的一个分支节点。
例：三角图标修改如下代码使用即可换成自己的了：
disclosureOpenIcon:Embed(source='resource/region.png-600');
disclosureClosedIcon:Embed(source='resource/region.png-600');
*/
}

xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx" minWidth="955" minHeight="600">

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id="myTree"
showRoot="false"
labelField="@label"
itemRenderer="com.flex.tree.dynamicicontree.IconTreeRenderer">


package com.flex.tree.dynamicicontree
{
import flash.xml.*;
import mx.collections.*;
import mx.controls.Image;
import mx.controls.listClasses.*;
import mx.controls.treeClasses.*;
import mx.styles.StyleManager;
/*
* ICON Tree的渲染器
*/
public class IconTreeRenderer extends TreeItemRenderer
{
protected var myImage:ImageRenderer;
private var imageWidth:Number = 16;
private var imageHeight:Number = 16;
private static var defaultImg:String = "windows.png-600";
public function IconTreeRenderer ()
{
super();
}
override protected function createChildren():void
{
super.createChildren();
myImage = new ImageRenderer();
myImage.source = defaultImg;
myImage.width=imageWidth;
myImage.height=imageHeight;
myImage.setStyle( "verticalAlign", "middle" );
addChild(myImage);
}
//通过覆盖data方法来动态设置tree的节点图标
override public function set data(value:Object):void
{
super.data = value;
var imageSource:String=value.@iconName.toString();
if(imageSource!="")
{
myImage.source=imageSource;
}else{
myImage.source=defaultImg;
}
}
//隐藏原有图标，并设置它的坐标
override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void
{
super.updateDisplayList(unscaledWidth, unscaledHeight);
if(super.data !=null)
{
if (super.icon != null)
{
myImage.x = super.icon.x;
myImage.y = 2;
super.icon.visible=false;
}
else
{
myImage.x = super.label.x;
myImage.y = 2;
super.label.x = myImage.x + myImage.width + 17;
}
}
}
}
}
package com.flex.tree.dynamicicontree
{
import mx.controls.Image;
public class ImageRenderer extends Image
{
private var defaultURL:String = "assets/icon/";
public var iconName:String;
public function ImageRenderer()
{
super();
}
override public function set source(url:Object):void{
super.source = defaultURL + url;
iconName = url as String;
}
}
}