Question

我有以下itemrenderer

<?xml version="1.0" encoding="utf-8"?>
<s:MXAdvancedDataGridItemRenderer xmlns:fx="http://ns.adobe.com/mxml/2009" 
xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx"  focusEnabled="true">

<s:Label id="lblData" top="0" left="0" right="0" bottom="0" text="{listData.label}" />

<fx:Script>
    <![CDATA[
        import mx.events.FlexEvent;

        override public function set data(value:Object):void
        {
            if(value != null)
            {
                super.data = value;
                if(value.age >30 )
                    lblData.setStyle("backgroundColor","red");
                 else 
                    lblData.setStyle("backgroundColor","green"); 
            }
            //super.invalidateDisplayList();
        }

        override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void
        {
            super.updateDisplayList(unscaledWidth,unscaledHeight);
            if(super.data)
            {

            }
        }
    ]]>
</fx:Script>
</s:MXAdvancedDataGridItemRenderer>

我的问题是上面的逻辑应该在updtaeDisplayList中还是保留在set data（）本身中。两者的输出都很糟糕。如果我们从生命周期的角度考虑它，那么性能影响差异是什么。（繁重的计算应该推向帧渲染的末尾）

Answer 1

按照您的方式，我宁愿使用invalidateProperties()和commintProperties()。但是如何使用数据绑定？

<?xml version="1.0" encoding="utf-8"?>
<s:MXAdvancedDataGridItemRenderer xmlns:fx="http://ns.adobe.com/mxml/2009" 
xmlns:s="library://ns.adobe.com/flex/spark" xmlns:mx="library://ns.adobe.com/flex/mx"  focusEnabled="true">
    <s:Label top="0" left="0" right="0" bottom="0" text="{listData.label}" backgroundColor="{data.age > 30 ? `red` : `green`}" />
</s:MXAdvancedDataGridItemRenderer>

应该在哪里设置样式逻辑进入Itemrenderer重写方法

1 个答案: