Flex:自定义ItemRender重写set data时低级错误一例(附Box作ItemRender代码)

使用ActionScript做Render时一般都会重写set data以实现具体效果, 洒家每次犯过多次低级错误, 那便是忘记set data时super之.

忘记super的后果是数据可能不会正常显示, Datagrid可能在浮动/点击 Render时 所在行没反应.

显示不正常的, 如: http://liguoliang.com/2009/10/1071/

附: 重写Box作为ItemRender代码(该类作为一个抽象出来专用于重写的Abstract类, 所以并未实现具体效果):

/*
* $Id$
* Copyright (c) 2008-2010 Insprise Software (Shanghai) Co. Ltd.
* All Rights Reserved
* Changelog:
*   LiGuoliang.com - Aug 15, 2010: Initial version
*/

package com.insprise.util.speedtest.lib
{

/**
 * SpeedTester的速度Render.
 */
[ResourceBundle('canvas_main')]
public class AbstractRenderForSpeed extends Box implements IDropInListItemRenderer, IListItemRenderer
{
	public static const RM:IResourceManager = ResourceManager.getInstance();
	public static const BUNDLE_CANVAS_MAIN:String = "canvas_main";

	/** Data */
	protected var _speedTester:SpeedTester; // 当前数据

	/** UI */
	protected var _progressBar:ProgressBar;

	protected var numberFormatter:NumberFormatter = SpeedTesterUtils.getNumFormatterForSpped();

	private var _listData:BaseListData; // 为实现IDropInListItemRenderer而创建.

	// Constructor
	public function AbstractRenderForSpeed() {
		super();
		direction = BoxDirection.HORIZONTAL; // 设置Box方向
	}

	/** @inheritDoc */
	public function get listData():BaseListData {
		return _listData;
	}

	/** @inheritDoc */
	public function set listData(value:BaseListData):void {
		_listData = value;
	}

	/** @inheritDoc */
	override protected function createChildren():void {
		_progressBar = new ProgressBar();
		_progressBar.mode = ProgressBarMode.MANUAL; // 设置Mode为手动, 以手动设置进度
		_progressBar.labelPlacement = ProgressBarLabelPlacement.CENTER; // 设置Label位置
		addChild(_progressBar);
	}

	/** @inheritDoc */
	override public function set data(value:Object):void {
		super.data = value; // 不能忘啊不能忘!
		if(_speedTester == value) {
			return;
		}

		_speedTester = value as SpeedTester;

		updateUI....; // 更新UI等操作
	}

} // end class
} // end package