django自定义分页器

Posted 2020-11-29 harrytree

因为django自带的分页封装的太死了，所以一般都不用，需要自己定义分页器，如下：

import  os

class Pagination(object):
    def __init__(self, current_page, all_count, per_page_num=8, 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

        用法:
        queryset = model.objects.all()
        page_obj = Pagination(current_page,all_count)
        page_data = queryset[page_obj.start:page_obj.end]
        获取数据用page_data而不再使用原始的queryset
        获取前端分页样式用page_obj.page_html
        """
        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‘>
                ‘‘‘ + os.linesep)
        first_page = ‘<li><a href="?page=%s">首页</a></li>‘ % (1) + os.linesep
        page_html_list.append(first_page)

        if self.current_page <= 1:
            prev_page = ‘<li class="disabled"><a href="#">上一页</a></li>‘  + os.linesep
        else:
            prev_page = ‘<li><a href="?page=%s">上一页</a></li>‘ % (self.current_page - 1,)  + os.linesep

        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,)   + os.linesep
            else:
                temp = ‘<li><a href="?page=%s">%s</a></li>‘ % (i, i,)  + os.linesep
            page_html_list.append(temp)

        if self.current_page >= self.all_pager:
            next_page = ‘<li class="disabled"><a href="#">下一页</a></li>‘  + os.linesep
        else:
            next_page = ‘<li><a href="?page=%s">下一页</a></li>‘ % (self.current_page + 1,)  + os.linesep
        page_html_list.append(next_page)

        last_page = ‘<li><a href="?page=%s">尾页</a></li>‘ % (self.all_pager,)  + os.linesep
        page_html_list.append(last_page)
        # 尾部添加标签
        page_html_list.append(‘‘‘
                                           </nav>
                                           </ul>
                                       ‘‘‘ + os.linesep  )
        return ‘‘.join(page_html_list)


if __name__ == "__main__":
    show_list = []
    for i in range(20):
        show_list.append(  "showlist" + str(i) )
    page_obj = Pagination( 3, 20)
    print(  page_obj.page_html())
    print( page_obj.start)
    print(page_obj.end)

    f = show_list[ page_obj.start: page_obj.end]
    print(f)

执行后打印结果如下：

"D:Program Filespython3.6.7python.exe" D:/pythonWorkspace/untitled1019/test/test2.py

                    <nav aria-label=‘Page navigation>‘
                    <ul class=‘pagination‘>
                
<li><a href="?page=1">首页</a></li>
<li><a href="?page=2">上一页</a></li>
<li><a href="?page=1">1</a></li>
<li><a href="?page=2">2</a></li>
<li class="active"><a href="?page=3">3</a></li>
<li class="disabled"><a href="#">下一页</a></li>
<li><a href="?page=3">尾页</a></li>

                                           </nav>
                                           </ul>
                                       

16
24
[‘showlist16‘, ‘showlist17‘, ‘showlist18‘, ‘showlist19‘]

Process finished with exit code 0

 

将这段代码放入html中测试：

<!DOCTYPE html>
<html>

<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">


<body>


 <nav aria-label=‘Page navigation>‘
                    <ul class=‘pagination‘>
                
<li><a href="?page=1">首页</a></li>
<li><a href="?page=2">上一页</a></li>
<li><a href="?page=1">1</a></li>
<li><a href="?page=2">2</a></li>
<li class="active"><a href="?page=3">3</a></li>
<li class="disabled"><a href="#">下一页</a></li>
<li><a href="?page=3">尾页</a></li>

                                           </nav>
                                           </ul>



</body>


</html>

执行结果如下：