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Detailed explanation of the process of turning the previous page to the next page in php

coldplay.xixi

Aug 01, 2020 pm 04:36 PM

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前言

这几天做项目因为数据太多，需要对信息进行上下翻页展示，就自己写了翻页的代码
大致功能就是页面只显示几条信息，按上一页、下一页切换内容，当显示第一页时上一页和首页选项不可选，当页面加载到最后一页时下一页和尾页选项不可选

具体效果如下：

相关学习推荐：PHP编程从入门到精通

实现代码

1）原生PHP方法

先说一下总思路吧，首先我们要查询所有符合条件需要进行分页的总数据，计算展示的总页数。

然后获取当前显示的是第几页信息，用当前页数每页数据条数表示为总数据的第几条，再根据限制条件查询出当前页所需显示出来的数据。将每一条数据echo替换HTML结构内容中，最后显示出来

关于分页的限制条件很简单，只要查询到当前页为第1页时，首页和上一页选项跳转链接都固定在第一页同时设置选项disabled不可选，尾页也是相同的步骤。

具体代码如下：

当前页cPage需要传过来，我的办法是初始cPage=0

list.php*

<a href="listmore.php?cPage=0" rel="external nofollow" rel="external nofollow" class="pull-right">更多>></a>
$row=$table->fetch()每次读取一条信息，得到的是一个索引数组，代码里的$row[&#39;id&#39;]表示$row里面名为id的值，也可表示为$row.id

connect.php(连接数据库)

<?php
$link=new PDO("mysql:host=localhost;port=3306;dbname=db","root","");
$link->query("set names utf8");

listmore.php

 <ul id="list" class="media-list">
  <?php
    include_once(&#39;connect.php&#39;);
    $result = $link->query("select * from news");
    $total=$result->rowCount();//查询出来符合条件的总数
    $pages=ceil($total/4);//分页的总页数  
    $num = 4;//每页显示的数据条数
    $cPage = $_GET[&#39;cPage&#39;];//获取当前是显示的第几页
    $start = $cPage * $num;//第一条数据
    $table = $link->query("select * from news order by id desc limit {$start},$num");
    $link = null;//销毁
    while ($row=$table->fetch()){//每次读出一条数据，赋给$row
      //插入多行文本，把值替换掉
    echo <<<_
      <li class="media">
        <a href="detail.php?id={$row[&#39;id&#39;]}">
        <img  class="pull-left lazy"  src="/static/imghwm/default1.png"  data-src="{$row[&#39;src&#39;]}"    alt="Detailed explanation of the process of turning the previous page to the next page in php" >
        <figcaption>
        <h4 id="span-nbsp-class-title-row-title-span-nbsp-span-nbsp-class-news-date-row-time-span"><span class="title">{$row[&#39;title&#39;]}</span> <span class="news-date">{$row[&#39;time&#39;]}</span></h4>
        <p>{$row[&#39;content&#39;]}</p>
        </figcaption>
        </a>
      </li>
  _;
    }
  ?>
</ul>

上下翻页：

<p class="page text-center">
 <ul class="pagination" id="page">
  <li data-i="0" id="index" class="<?php if ($cPage==0) echo &#39;disabled&#39;; ?>"><a href="listmore.php?cPage=0">&laquo;首页</a></li>
  <li data-i="1" class="<?php if ($cPage==0) echo &#39;disabled&#39;;?>"><a href="listmore.php?cPage=<?php echo $cPage>0?$cPage-1:0?>"><上一页</a></li>
  <li data-i="2" class="<?php if ($cPage==$pages-1) echo &#39;disabled&#39;?>"><a href="listmore.php?cPage=<?php echo $cPage==($pages-1)?$pages-1:$cPage+1?>">下一页></a></li>
  <li data-i="3" id="end" class="<?php if ($cPage==$pages-1) echo &#39;disabled&#39;?>"><a href="listmore.php?cPage=<?php echo $pages-1?>">尾页&raquo;</a></li>
  <li class="disabled">
    <a href="##" id="total"><?php echo ($cPage+1)?>/<?php echo "$pages"?></a>
  </li>
  </ul>
</p>

2)ajax方法

HTML代码，展示信息装在panel-body里面

 <p class="panel-body" id="content">
    <ul id="list" class="media-list">  
     </ul>
  </p>
  <p class="page text-center">
     <ul class="pagination" id="page">
       <li data-i="0" id="index" class="disabled"><a href="##">&laquo;首页</a></li>
       <li data-i="1" class="disabled"><a href="##"><上一页</a></li>
       <li data-i="2"><a href="##">下一页></a></li>
       <li data-i="3" id="end"><a href="##">尾页&raquo;</a></li>
       <li class="disabled">
         <a href="##" id="total"></a>
       </li>
     </ul>
   </p>
   <template id="temp">     //引用模板
    <li class="media">
      <a href="detail.html?id={id}">
        <img  class="pull-left lazy"  src="/static/imghwm/default1.png"  data-src="{src}"    alt="Detailed explanation of the process of turning the previous page to the next page in php" >
        <figcaption>
          <h4 id="span-nbsp-class-title-title-span-nbsp-span-nbsp-class-news-date-date-span"><span class="title">{title}</span> <span class="news-date">{date}</span></h4>
  
          <p>{content}</p>
         </figcaption>
        </a>
      </li>
    </template>

JS代码：

 var html=$(&#39;#temp&#39;).html();
  var curPage=0,pages=0;
  $.getJSON(&#39;php/pages.php&#39;,function (res) {
    pages=Math.ceil(res/4);/*获取信息的总页数*/
  });
  function show(cPage){//替换每一页的内容
    $.getJSON(&#39;php/listmore.php&#39;,{cPage:cPage},function (json) {
      var str=&#39;&#39;;
      $(&#39;#list&#39;).empty();
      json.forEach(function (el) {
        str+=html.replace(&#39;{id}&#39;,el.id).replace(&#39;{title}&#39;,el.title).replace(&#39;{src}&#39;,el.src)
          .replace(&#39;{content}&#39;,el.content).replace(&#39;{date}&#39;,el.time);
      });
      $(&#39;#list&#39;).html(str);
    });
    $(&#39;#total&#39;).html((curPage+1)+&#39;/&#39;+pages);
  }
  setTimeout(function () {
    show(0);
  },100);
  $(&#39;#page&#39;).on(&#39;click&#39;,&#39;li&#39;,function () {//上下翻页，翻遍当前页的值
    var i=$(this).data(&#39;i&#39;);//jquery里特有的获取data-*属性的方法
    switch (i){
      case 0:curPage=0;break;
      case 1:curPage>0?curPage--:0;break;
      case 2:curPage<(pages-1)?curPage++:pages-1;break;
      case 3:curPage=pages-1;break;
    }
    show(curPage);
    disabled(curPage);
  })
  function disabled(curPage) {//关于临界值禁止选择
    if (curPage==0){/*当前页为第一页，首页和上一页选项禁止点击*/
      $(&#39;#index&#39;).addClass(&#39;disabled&#39;).next().addClass(&#39;disabled&#39;);
      $(&#39;#end&#39;).removeClass(&#39;disabled&#39;).prev().removeClass(&#39;disabled&#39;);
    } else if (curPage==pages-1){
      $(&#39;#index&#39;).removeClass(&#39;disabled&#39;).next().removeClass(&#39;disabled&#39;);
      $(&#39;#end&#39;).addClass(&#39;disabled&#39;).prev().addClass(&#39;disabled&#39;);
    } else {/*当前页为最后一页，尾页和下一页选项禁止点击*/
      $(&#39;#index&#39;).removeClass(&#39;disabled&#39;).next().removeClass(&#39;disabled&#39;);
      $(&#39;#end&#39;).removeClass(&#39;disabled&#39;).prev().removeClass(&#39;disabled&#39;);
    }
  }

connect.php(连接数据库)

<?php
$link=new PDO("mysql:host=localhost;port=3306;dbname=db","root","");
$link->query("set names utf8");

pages.php（获取总页数）

<?php
include_once(&#39;connect.php&#39;);//连接数据库
$result = $link->query("select * from news");
$row=$result->rowCount();
echo $row;

listmore.php（获取数据库里的数据）

<?php
include_once (&#39;connect.php&#39;);
$num = 4;//每一页显示的数据条数
$cPage = $_GET[&#39;cPage&#39;];//获取当前页
$start = $cPage * $num;//计算当前页显示的第一条数据的数目
/*从表中查询从开始$start的一共$num条数据*/
$result = $link->query("select * from news order by id desc limit {$start},$num");
$link = null;
while ($row=$result->fetch()){/*每一次读取一条数据*/
$json[]=$row;/*把数据赋给json数组*/
}
echo json_encode($json);/*把json数组以json格式返回给HTML*/

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