Django自定义分页器

Posted 2021-03-11 cnhyk

自定义分页器，用于django在后端查询出来的数据，展示到前端页面，以分页的形式展示出来。

1、将封装好的代码，写入py文件中，例如：mypagination.py

# mypagination.py
 
class Pagination(object):
    def __init__(self, current_page, all_count, per_page_num=10, pager_count=11):
        """
        封装分页相关数据
        :param current_page: 当前页
        :param all_count:    数据库中的数据总条数
        :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 = int(current_page)
        except Exception as e:
            current_page = 1
 
        if current_page < 1:
            current_page = 1
 
        self.current_page = current_page
 
        self.all_count = all_count
        self.per_page_num = per_page_num
 
        # 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)
 
    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_num
 
    @property
    def end(self):
        return self.current_page * self.per_page_num
 
    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 <= 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 + self.pager_count_half) > self.all_pager:
                    pager_end = self.all_pager + 1
                    pager_start = self.all_pager - self.pager_count + 1
                else:
                    pager_start = self.current_page - self.pager_count_half
                    pager_end = self.current_page + self.pager_count_half + 1
 
        page_html_list = []
        # 添加前面的nav和ul标签
        page_html_list.append('''
                    <nav aria-label='Page navigation>'
                    <ul class='pagination'>
                ''')
        first_page = '<li><a href="?page=%s">首页</a></li>' % (1)
        page_html_list.append(first_page)
 
        if self.current_page <= 1:
            prev_page = '<li class="disabled"><a href="#">上一页</a></li>'
        else:
            prev_page = '<li><a href="?page=%s">上一页</a></li>' % (self.current_page - 1,)
 
        page_html_list.append(prev_page)
 
        for i in range(pager_start, pager_end):
            if i == self.current_page:
                temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i,)
            else:
                temp = '<li><a href="?page=%s">%s</a></li>' % (i, i,)
            page_html_list.append(temp)
 
        if self.current_page >= self.all_pager:
            next_page = '<li class="disabled"><a href="#">下一页</a></li>'
        else:
            next_page = '<li><a href="?page=%s">下一页</a></li>' % (self.current_page + 1,)
        page_html_list.append(next_page)
 
        last_page = '<li><a href="?page=%s">尾页</a></li>' % (self.all_pager,)
        page_html_list.append(last_page)
        # 尾部添加标签
        page_html_list.append('''
                                           </nav>
                                           </ul>
                                       ''')
        return ''.join(page_html_list)

2、导入后端，将查询的数据交给自定义分页器处理，然后再返回给前端

# 示例一
from app01.utils.mypagination import Pagination
 
 
def home(request):
    # 将网站所有的文章全部查询出来展示到前端
    article_list = models.Article.objects.all()
    page_obj = Pagination(current_page=request.GET.get('page', 1), all_count=article_list.count())
    page_queryset = article_list[page_obj.start:page_obj.end]
    return render(request, 'home.html', locals())
 
 
# 示例二
from mypagination import Pagination
 
def get_book(request):
   book_list = models.Book.objects.all()
   current_page = request.GET.get("page",1)
   all_count = book_list.count()
   page_obj = Pagination(current_page=current_page,all_count=all_count,per_page_num=10)
   page_queryset = book_list[page_obj.start:page_obj.end]
   return render(request,'booklist.html',locals())

3、前端渲染

<!--示例一-->
        <div class="col-md-8">
            <ul class="media-list">
                {% for article_obj in page_queryset %}
                    <li class="media">
                    <h4 class="media-heading"><a href="#">{{ article_obj.title }}</a></h4>
                    <div class="media-left">
                        <a href="#">
                            <img class="media-object" src="/static/image/default.jpg" alt="..." width="60">
                        </a>
                    </div>
                    <div class="media-body">
                        {{ article_obj.desc }}
                    </div>
                        <br>
                    <div>
                        <span><a href="#">{{ article_obj.blog.userinfo.username }}</a>&nbsp;</span>
                        <span>发布于&nbsp;</span>
                        <span>{{ article_obj.create_time|date:'Y-m-d' }}&nbsp;&nbsp;</span>
                        <span>评论（{{ article_obj.comment_num }}）&nbsp;&nbsp;</span>
                        <span>点赞（{{ article_obj.up_num }}）</span>
                    </div>
                </li>
                    <hr>
                {% endfor %}
            </ul>
            <!--分页器-->
        <div class="text-center">{{ page_obj.page_html|safe }}</div>
        </div>
 
 
<!--示例二-->
<div class="container">
    <div class="row">
        <div class="col-md-8 col-md-offset-2">
            <!--使用for循环，将后端传过来的多条数据渲染出来-->
            {% for book in page_queryset %}
            <p>{{ book.title }}</p>
            {% endfor %}
            <!--分页器-->
            {{ page_obj.page_html|safe }}
        </div>
    </div>
</div>