php自定义分页类的原理

<?php
header("Content-type:text/html;Charset=utf-8");
class SubPages{
 private $each_disNums;//每页显示的条目数
 private $nums;//总条目数
 private $current_page;//当前被选中的页
 private $sub_pages;//每次显示的页数
 private $pageNums;//总页数
 private $page_array = array();//用来构造分页的数组
 private $subPage_link;//每个分页的链接
 //private $subPage_type;//显示分页的类型
/*
  当@subPage_type=1的时候为普通分页模式
     example：  共4523条记录,每页显示10条,当前第1/453页 [首页] [上页] [下页] [尾页]
     当@subPage_type=2的时候为经典分页样式
     example：  当前第1/453页 [首页] [上页] 1 2 3 4 5 6 7 8 9 10 [下页] [尾页]
 */
 function __construct($each_disNums,$nums,$current_page,$sub_pages,$subPage_link){
  $this->each_disNums=intval($each_disNums);
 $this->nums=intval($nums);
 if(!$current_page){
 $this->current_page=1;
 }else{
   $this->current_page=intval($current_page);
  }
 $this->sub_pages=intval($sub_pages);
  $this->pageNums=ceil($nums/$each_disNums);
  $this->subPage_link=$subPage_link;
  // $this->show_SubPages($subPage_type);
 }
  // show_SubPages函数用在构造函数里面。而且用来判断显示什么样子的分页
 /* function show_SubPages($subPage_type){
   if($subPage_type == 1){
   $this->subPageCss1();
   }else if ($subPage_type == 2){
   $this->subPageCss2();
   }
  }
*/
  //用来给建立分页的数组初始化的函数。
 function initArray(){
   for($i=0;$i<$this->sub_pages;$i++){
   $this->page_array[$i]=$i;
 }
   return $this->page_array;
  }
  /* construct_num_Page该函数使用来构造显示的条目
  即使：[1][2][3][4][5][6][7][8][9][10] */
 function construct_num_Page(){
  if($this->pageNums < $this->sub_pages){
   $current_array=array();
   for($i=0;$i<$this->pageNums;$i++){
    $current_array[$i]=$i+1;
   }
   }else{
   $current_array=$this->initArray();
   if($this->current_page <= 3){
    for($i=0;$i<count($current_array);$i++){
     $current_array[$i]=$i+1;
    }
   }else if ($this->current_page <= $this->pageNums && $this->current_page > $this->pageNums - $this->sub_pages + 1 ){
    for($i=0;$i<count($current_array);$i++){
     $current_array[$i]=($this->pageNums)-($this->sub_pages)+1+$i;
    }
   }else{
    for($i=0;$i<count($current_array);$i++){
     $current_array[$i]=$this->current_page-2+$i;
    }
   }
  }
  return $current_array;
  }
 /*
  构造普通模式的分页
  共4523条记录,每页显示10条,当前第1/453页 [首页] [上页] [下页] [尾页]
  */
 function subPageCss1(){
  $subPageCss1Str="";
  $subPageCss1Str.="共".$this->nums."条记录，";
  $subPageCss1Str.="每页显示".$this->each_disNums."条，";
  $subPageCss1Str.="当前第".$this->current_page."/".$this->pageNums."页 ";
  if($this->current_page > 1){
   $firstPageUrl=$this->subPage_link."1";
   $prewPageUrl=$this->subPage_link.($this->current_page-1);
   $subPageCss1Str.="[<a href=&#39;$firstPageUrl&#39;>首页</a>] ";
   $subPageCss1Str.="[<a href=&#39;$prewPageUrl&#39;>上一页</a>] ";
  }else {
   $subPageCss1Str.="[首页] ";
   $subPageCss1Str.="[上一页] ";
  }
  if($this->current_page < $this->pageNums){
   $lastPageUrl=$this->subPage_link.$this->pageNums;
   $nextPageUrl=$this->subPage_link.($this->current_page+1);
   $subPageCss1Str.=" [<a href=&#39;$nextPageUrl&#39;>下一页</a>] ";
   $subPageCss1Str.="[<a href=&#39;$lastPageUrl&#39;>尾页</a>] ";
  }else {
   $subPageCss1Str.="[下一页] ";
   $subPageCss1Str.="[尾页]";
  }
  return $subPageCss1Str; //在此可以设置显示的CSS样式
  }
 /*
  构造经典模式的分页
  当前第1/453页 [首页] [上页] 1 2 3 4 5 6 7 8 9 10 [下页] [尾页]
  */
 function subPageCss2(){
  $subPageCss2Str="";
  $subPageCss2Str.="当前第".$this->current_page."/".$this->pageNums."页 ";
 if($this->current_page > 1){
   $firstPageUrl=$this->subPage_link."1";
   $prewPageUrl=$this->subPage_link.($this->current_page-1);
   $subPageCss2Str.="[<a href=&#39;$firstPageUrl&#39;>首页</a>] ";
   $subPageCss2Str.="[<a href=&#39;$prewPageUrl&#39;>上一页</a>] ";
  }else {
   $subPageCss2Str.="[首页] ";
   $subPageCss2Str.="[上一页] ";
  }
 $a=$this->construct_num_Page();
  for($i=0;$i<count($a);$i++){
   $s=$a[$i];
   if($s == $this->current_page ){
    $subPageCss2Str.="[<span style=&#39;color:red;font-weight:bold;&#39;>".$s."</span>]";
   }else{
    $url=$this->subPage_link.$s;
    $subPageCss2Str.="[<a href=&#39;$url&#39;>".$s."</a>]";
   }
  }
  if($this->current_page < $this->pageNums){
   $lastPageUrl=$this->subPage_link.$this->pageNums;
   $nextPageUrl=$this->subPage_link.($this->current_page+1);
   $subPageCss2Str.=" [<a href=&#39;$nextPageUrl&#39;>下一页</a>] ";
   $subPageCss2Str.="[<a href=&#39;$lastPageUrl&#39;>尾页</a>] ";
  }else {
   $subPageCss2Str.="[下一页] ";
   $subPageCss2Str.="[尾页] ";
  }
  return $subPageCss2Str;
  }
}
//使用如下
/*include(&#39;../mysql.php&#39;);
//每页显示的条数
 $page_size=3;
//总条目数
$sql=mysql_query("select * from `stu_info`");
$nums=mysql_num_rows($sql);
//每次显示的页数
 $sub_pages=10;
//得到当前是第几页
 if(!isset($_GET["p"])){
 $pageCurrent=1;
 }else{
  $pageCurrent=$_GET["p"];
 }
 $subPages=new SubPages($page_size,$nums,$pageCurrent,$sub_pages,"page.php?p=");
 $page=$subPages->subPageCss2();
 echo $page;//在此可以设置CSS样式
 $ss=mysql_query("select * from `stu_info` limit ".$page_size*($pageCurrent-1).",".$page_size);
 while($row=mysql_fetch_array($ss)){
 echo $row[&#39;stunum&#39;].&#39;&#39;.$row[&#39;stuname&#39;].&#39;&#39;.$row[&#39;clanum&#39;].&#39;<br>&#39;;
 }*/
?>