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:

Django 自定义分页器的实现代码

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

Django 自定义分页器的实现代码

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="" 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="" 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="" rel="external nofollow" rel="external nofollow" >%s</a></li>' % (self.params.urlencode(), i)
      else:
        temp = '<li><a href="" 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="" 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="" 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。

华山资源网 Design By www.eoogi.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
华山资源网 Design By www.eoogi.com

稳了!魔兽国服回归的3条重磅消息!官宣时间再确认!

昨天有一位朋友在大神群里分享,自己亚服账号被封号之后居然弹出了国服的封号信息对话框。

这里面让他访问的是一个国服的战网网址,com.cn和后面的zh都非常明白地表明这就是国服战网。

而他在复制这个网址并且进行登录之后,确实是网易的网址,也就是我们熟悉的停服之后国服发布的暴雪游戏产品运营到期开放退款的说明。这是一件比较奇怪的事情,因为以前都没有出现这样的情况,现在突然提示跳转到国服战网的网址,是不是说明了简体中文客户端已经开始进行更新了呢?