<?php/*核心:首頁(yè)、上一頁(yè)、下一頁(yè)、尾頁(yè)的url*//*超全局$_SERVER*/$page = new Page(5,60);var_dump($page->allUrl());class Page{//   每頁(yè)顯示的個(gè)數(shù)  protected $number;//   一共有多少數(shù)據(jù)  protected $totalCount;//   當(dāng)前頁(yè)  protected $page;//   url  protected $url;    public function __construct($number,$totalCount){    $this->number= $number;    $this->totalCount = $totalCount;    //得到總頁(yè)數(shù)    $this->totalPage = $this->getTotalPage();    //得到當(dāng)前頁(yè)數(shù)    $this->page = $this->getPage();    //得到URL    $this->url = $this->getUrl();    echo $this->url;  }  /*得到總頁(yè)數(shù)并向上取整*/  protected function getTotalPage(){    return   ceil($this->totalCount/$this->number);  }  /**/  protected function getPage(){    if (empty($_GET['page'])){      $page=1;    }elseif ($_GET['page'] > $this->totalPage){      $page = $this->totalPage;    }elseif ($_GET["page"]<1){      $page = 1;    }else{      $page = $_GET['page'];    }    return $page;  }  protected function getUrl(){    //得到協(xié)議名    $scheme = $_SERVER['REQUEST_SCHEME'];    //得到主機(jī)名    $host= $_SERVER['SERVER_NAME'];    //得到端口號(hào)    $port = $_SERVER['SERVER_PORT'];    //得到路徑和請(qǐng)求字符串    $url = $_SERVER['REQUEST_URI'];    /*中間做處理,要將page=5等這種字符串拼接URL    中，所以如果原來(lái)的url中有page這個(gè)參數(shù)，我們首先    需要將原來(lái)的page參數(shù)給清空*/    $urlArray = parse_url($url);//     var_dump($urlArray);    $path = $urlArray['path'];    if (!empty($urlArray['query'])){      //將query中的值轉(zhuǎn)化為數(shù)組      parse_str($urlArray['query'],$array);      //如果他有page就將它刪掉      unset($array['page']);      //將關(guān)聯(lián)數(shù)組轉(zhuǎn)化為query      $query = http_build_query($array);      //不為空的話(huà)就與path連結(jié)      if ($query != ''){        $path = $path.'?'.$query;      }    }    return 'http://'. $host.':'.$port.$path;  }  protected function setUrl($str){    if (strstr($this->url, '?')){      $url = $this->url.'&'.$str;    }else{      $url = $this->url.'?'.$str;    }    return $url;  }  /*所有的url*/  public function allUrl(){    return [      'first' => $this->first(),      'next' => $this->next(),      'prev'=> $this->prev(),      'end'=> $this->end(),    ];  }  /*首頁(yè)*/  public function first(){    return $this->setUrl('page=1');  }  /*下一頁(yè)*/  public function next(){    //根據(jù)當(dāng)前page得帶下一頁(yè)的頁(yè)碼    if ($this->page+1 > $this->totalPage) {      $page = $this->totalPage;    }else{      $page = $this->page+1;    }    return $this->setUrl('page='.$page);  }  /*上一頁(yè)*/  public function prev(){    //根據(jù)當(dāng)前page得帶下一頁(yè)的頁(yè)碼    if ($this->page - 1 < 1) {      $page = 1;    }else{      $page = $this->page-1;    }    return $this->setUrl('page='.$page);  }  /*尾頁(yè)*/  public function end(){    return $this->setUrl('page='.$this->totalPage);  }  /*limit 0,5*/  public function limit(){    $offset = ($this->page-1)*$this->number;    return $offset.','.$this->number;  }  }