Flex 自定义DataGrid实现根据条目某一属性值改变背景颜色

package czgh.components 
{ 
import flash.display.sprite; 

import mx.controls.datagrid; 
import mx.core.uicomponent; 

public class optionaldatagrid extends datagrid 
{ 
private var _rowcolorfunction:function; 
private var _customed:boolean; 
private var _customercolor:uint=0; 
public function optionaldatagrid() 
{ 
super(); 
} 

override protected function drawrowbackground(s:sprite, rowindex:int, y:number, height:number, color:uint, dataindex:int):void 
{ 
color=0xffffff; 

if(this._rowcolorfunction != null) 
{ 
if (dataindex < this.dataprovider.length) 
{ 
var item:object=this.dataprovider.getitemat(dataindex);//设定颜色 
color=this._rowcolorfunction.call(this, item, color); 
} 
} 



super.drawrowbackground(s, rowindex, y, height, color, dataindex); 
} 

override protected function drawheaderbackground(headerbg:uicomponent):void 
{ 
headerbg.setstyle("bordervisible","false"); 
} 



public function set rowcolorfunction(rowcolorfunction:function):void 
{ 
this._rowcolorfunction=rowcolorfunction; 
} 

public function get rowcolorfunction():function 
{ 
return this._rowcolorfunction; 
} 


} 
}

//通过比较每条记录中datafield为act和stand的大小决定该条记录的背景颜色 
private function setcustomcolor(item:object, color:uint):uint 
{ 
if (number(item["act"])<number(item["stand"])) 
{ 
return 0x7bbfea; 
} 

return color; 
}