flex分页

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" xmlns="*" layout="absolute" creationComplete="initApp()">
 <mx:Script>
  <![CDATA[
   public var pageRecordes:uint = 8;
   public var totalPages:uint = 0;
   public var totalRows:uint = 0;
   public var currentPage:uint = 1;
   public var pageStartRow:uint = 1;
   public var pageEndRow:uint = 0;
  
   public function initApp():void{
     txt.text = "Page " + currentPage;
     totalRows = initDG.length;
     if(initDG.length > pageRecordes){
      dg.dataProvider = initDG.slice(0,pageRecordes);
      pPage.enabled = false;
     }
    
     if((totalRows % pageRecordes) == 0){
       totalPages = Math.floor(totalRows / pageRecordes);
     }else{
      totalPages = Math.floor(totalRows / pageRecordes + 1);
     }
    
     if(totalRows <= pageRecordes){
      this.pageStartRow = 1;
      this.pageEndRow = totalRows;
      } else {
      this.pageStartRow = 1;
      this.pageEndRow = pageRecordes;
     }
    
     if(totalPages == 1){
      pPage.enabled = false;
      nPage.enabled = false;
     }   
   }
  
   public function showPreviousPage():void{
     currentPage = currentPage - 1;