datagrid中修改背景颜色式样

以下转载官方文档
//http://www.adobe.com/devnet/flash/quickstart/datagrid_pt3.html

啥都不多说了，老外的文档注释说得已经很详细了。直接上代码
package { 
// Import the required component classes. 
 import fl.controls.listClasses.CellRenderer;
 import fl.controls.listClasses.ICellRenderer; 
 
 /** * This class sets the upSkin style based on the current item's index in a list. 
 * Make sure the class is marked "public" and in the case of our custom cell renderer, * extends the CellRenderer class and implements the ICellRenderer interface.  */ 
 
 public class AlternatingRowColors extends CellRenderer implements ICellRenderer {
      /** * Constructor. */ 
  		public function AlternatingRowColors():void { 
  			super();
   		} 
   		
       /** * This method returns the style definition object from the CellRenderer class. */ 
  		public static function getStyleDefinition():Object 
  		{ 
  			return CellRenderer.getStyleDefinition();
   		} 
  
      /** * This method overrides the inherited drawBackground() method and sets    the renderer's * upSkin style based on the row's current index. For example, if the row index is an * odd number,the upSkin style is set to the CellRenderer_upSkinDarkGray linkage in the * library. If the row index is an even number, the upSkin style is set to the * CellRenderer_upSkinGray 
      linkage in the library. 
      */ 
   		override protected function drawBackground():void { 
   			if (_listData.index % 2 == 0) { 
   				setStyle("upSkin", CellRenderer_upSkinGray);
    		} 
    		else{ 
    			setStyle("upSkin", CellRenderer_upSkinDarkGray);
    		}
    		 super.drawBackground(); 
    		 } 
    	} 
 }