Django 自定义分页器的实现代码

框架(架构)  /  管理员 发布于 7年前   197

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="https:/article/?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="https:/article/?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="https:/article/?%s" rel="external nofollow" rel="external nofollow" >%s</a></li>' % (self.params.urlencode(), i)      else:        temp = '<li><a href="https:/article/?%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="https:/article/?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="https:/article/?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 Paginationfrom myapp.models import Userdef 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/[email protected]/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>

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