Generate serial number using labelFunction in datagrid

MXML File

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" >
<mx:Script>
    <![CDATA[
        import mx.rpc.events.ResultEvent;
       
        public function Gridview():void
        {
              numberdata.dataProvider=Xmldata.subnumber;
        }
       
        /* ***************** Serial Number Loading **************** */
        private function serialLabelFunction(item:Object, column:DataGridColumn):String
        {
            var index:int =numberdata.dataProvider.getItemIndex(item);
            if (index > -1)
                return (index + 1).toString();
            
            return "";
        }
    ]]>
</mx:Script>
<mx:XML xmlns="" id="Xmldata">
 <senumber>
<subnumber name="kaniskar" designation="FlexDeveloper"/>
<subnumber name="Banupriya" designation="Auditing"/>
<subnumber name="kaniskar" designation="FlexDeveloper"/>
<subnumber name="Banupriya" designation="Auditing"/>
<subnumber name="kaniskar" designation="FlexDeveloper"/>
<subnumber name="Banupriya" designation="Auditing"/>
<subnumber name="kaniskar" designation="FlexDeveloper"/>
<subnumber name="Banupriya" designation="Auditing"/>
<subnumber name="kaniskar" designation="FlexDeveloper"/>
<subnumber name="Banupriya" designation="Auditing"/>
</senumber>
</mx:XML>
<mx:DataGrid width="500" height="400" id="numberdata" sortableColumns="false">
    <mx:columns>
        <mx:DataGridColumn headerText="SerialNumber" labelFunction="serialLabelFunction"/>
        <mx:DataGridColumn headerText="Name" dataField="@name"/>
        <mx:DataGridColumn headerText="Designation" dataField="@designation"/>
    </mx:columns>
</mx:DataGrid>
    <mx:Button x="416" y="418" label="Load Data" click="Gridview()"/>
</mx:Application>

Output

Generate serial number using labelFunction in datagrid Demo