python

超轻量级php框架startmvc

Django 自定义分页器的实现代码

更新时间:2020-08-09 22:24:02 作者:startmvc
为什么要实现分页?在大部分网站中分页的功能都是必要的,尤其是在后台管理中分页更是

为什么要实现分页?

在大部分网站中分页的功能都是必要的,尤其是在后台管理中分页更是不可或缺

分页能带给用户更好的体验,也能减轻服务器的压力

对于分页来说,有许多方法都可以实现

例如把数据全部读取出来在前端用javascript实现,但这样一次请求全部数据服务器压力很大,

还有就是在后端实现,每一次请求部分数据显示

分页需求:

1. 每页显示的多少条数据

2. 页面显示多少个页码

3. 上一页和下一页

4. 首页和尾页

效果演示:

代码实现:

分页类封装:

在我的app下创建一个page.py文件,进行封装,我是先在我的app下创建了一个utils文件再创建page.py


class Pagination(object):

 def __init__(self, current_page_num, all_count, request, per_page_num=10, pager_count=11):
 """
 封装分页相关数据
 :param current_page_num: 当前访问页的数字
 :param all_count: 分页数据中的数据总条数
 :param per_page_num: 每页显示的数据条数
 :param pager_count: 最多显示的页码个数
 """
 try:
 current_page_num = int(current_page_num)
 except Exception as e:
 current_page_num = 1

 if current_page_num < 1:
 current_page_num = 1

 self.current_page_num = current_page_num

 self.all_count = all_count
 self.per_page_num = per_page_num

 # 实际总页码
 all_pager, tmp = divmod(all_count, per_page_num)
 if tmp:
 all_pager += 1
 self.all_pager = all_pager

 self.pager_count = pager_count
 self.pager_count_half = int((pager_count - 1) / 2) # 5

 # 保存搜索条件
 import copy
 self.params = copy.deepcopy(request.GET) # {"a":"1","b":"2"}

 # 开始
 @property
 def start(self):
 return (self.current_page_num - 1) * self.per_page_num

 # 结束
 @property
 def end(self):
 return self.current_page_num * self.per_page_num

 # 实现
 def page_html(self):
 # 如果总页码 < 11个:
 if self.all_pager <= self.pager_count:
 pager_start = 1
 pager_end = self.all_pager + 1
 # 总页码 > 11
 else:
 # 当前页如果<=页面上最多显示11/2个页码
 if self.current_page_num <= self.pager_count_half:
 pager_start = 1
 pager_end = self.pager_count + 1
 # 当前页大于5
 else:
 # 页码翻到最后
 if (self.current_page_num + self.pager_count_half) > self.all_pager:

 pager_start = self.all_pager - self.pager_count + 1
 pager_end = self.all_pager + 1

 else:
 pager_start = self.current_page_num - self.pager_count_half
 pager_end = self.current_page_num + self.pager_count_half + 1

 page_html_list = []

 first_page = '<li><a href="?page=%s" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >首页</a></li>' % (1,)
 page_html_list.append(first_page)

 if self.current_page_num <= 1:
 prev_page = '<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" >上一页</a></li>'
 else:
 prev_page = '<li><a href="?page=%s" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >上一页</a></li>' % (self.current_page_num - 1,)

 page_html_list.append(prev_page)

 # self.params=copy.deepcopy(request.GET) # {"a":"1","b":"2"}

 for i in range(pager_start, pager_end):

 self.params["page"] = i

 if i == self.current_page_num:
 temp = '<li class="active"><a href="?%s" rel="external nofollow" rel="external nofollow" >%s</a></li>' % (self.params.urlencode(), i)
 else:
 temp = '<li><a href="?%s" rel="external nofollow" rel="external nofollow" >%s</a></li>' % (self.params.urlencode(), i,)
 page_html_list.append(temp)

 if self.current_page_num >= self.all_pager:
 next_page = '<li class="disabled"><a href="#" rel="external nofollow" rel="external nofollow" >下一页</a></li>'
 else:
 next_page = '<li><a href="?page=%s" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >下一页</a></li>' % (self.current_page_num + 1,)
 page_html_list.append(next_page)
 last_page = '<li><a href="?page=%s" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" >尾页</a></li>' % (self.all_pager,)
 page_html_list.append(last_page)

 return ''.join(page_html_list)

在视图中使用

views.py


# 首先导入包
from myapp.utils.page import Pagination
from myapp.models import User


def index(request):
 # queryset
 user_list = User.objects.all()
 # 总页数
 page_count = user_list.count()
 # 当前页
 current_page_num = request.GET.get("page")
 pagination = Pagination(current_page_num, page_count, request, per_page_num=1)
 # 处理之后的数据
 user_list = user_list[pagination.start:pagination.end]

 content = {
 "user_list": user_list,
 "pagination": pagination,
 }
 return render(request, "user_list.html", content)

页面显示

user_list.html


<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <title>index</title>
 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" rel="external nofollow" >
</head>
<body>
<div class="container">
 <table class="table table-striped">
 <thead>
 <tr>
 <th>name</th>
 </tr>
 </thead>
 <tbody>
 {% for user in user_list %}
 <tr>
 <td>{{ user.name }}</td>
 </tr>
 {% endfor %}
 </tbody>
 </table>
 <!-- bootstrap 样式 -->
 <div class="dataTables_paginate paging_simple_numbers pull-right">
 <ul class="pagination">
 {{ pagination.page_html|safe }}
 </ul>
 </div>
</div>
</body>
</html>

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。

Django 自定义分页器 Django 分页器 Django 分页