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  • Django之分页器组件与自定义

    Django之分页器组件一

    class Pagination(object):
    def __init__(self,current_page,all_count,per_page_num=2,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'>
                ''')
        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)
    

    分页器组件二

    paging.py

    • from django.utils.safestring import mark_safe
      
      
      class Paging:
      
          def __init__(self, total_count, per_page_count, per_page_page, current_page, data=None):
              """
              :param current_page:   当前页码
              :param total_count:    总数据量
              :param per_page_count:    每页显示多少条
              :param per_page_page:   总共显示多少个页码
              data: 可编辑Queryset对象
      
              start_page_number:起始页码
              end_page_number:结束页码
              """
      
              try:
                  current_page = int(current_page)
              except Exception:
                  current_page = 1
      
              half_number = per_page_page // 2
              a, b = divmod(total_count, per_page_count)
              # 如果余数不为0,页码总数为商+1
              if b:
                  total_page_count = a + 1
              else:
                  total_page_count = a
              # total_page_count 最大页数
              # 当当前页码小于等于0的时候,默认显示第一页
              if current_page >= total_page_count:
                  current_page = total_page_count
      
              if current_page <= 0:
                  current_page = 1
      
              # current_page 2
              # print(total_page_count)  # 2
              start_page_number = current_page - half_number  #
              end_page_number = current_page + half_number + 1  # 6
      
              if start_page_number <= 0:
                  start_page_number = 1
                  end_page_number = per_page_page + 1  # 7
      
              if end_page_number >= total_page_count:  # 6 > 2
                  start_page_number = total_page_count - per_page_page + 1  # -4
                  end_page_number = total_page_count + 1  # 3
      
              if total_page_count < per_page_page:
                  start_page_number = 1
                  end_page_number = total_page_count + 1
      
              self.current_page = current_page
              self.per_page_count = per_page_count
              self.total_page_count = total_page_count
              self.start_page_number = start_page_number
              self.end_page_number = end_page_number
              self.data = data
      
          @property
          def start_data_number(self):
      
              return (self.current_page - 1) * self.per_page_count
      
          @property
          def end_data_number(self):
      
              return self.current_page * self.per_page_count
      
          @property
          def paging_html(self):
      
              page_html = """
                         <nav aria-label="Page navigation">
                           <ul class="pagination">
      
                         """
              self.data["page"] = 1
              first_page = f"""
                             <li>
                               <a href="?{self.data.urlencode()}" aria-label="Previous">
                                 <span aria-hidden="true">首页</span>
                               </a>
                             </li>"""
              page_html += first_page
              self.data['page'] = self.current_page - 1
              previous_page = f"""
                         <li>
                               <a href="?{self.data.urlencode()}" aria-label="Previous">
                                 <span aria-hidden="true">&laquo;</span>
                               </a>
                             </li>"""
              page_html += previous_page
      
              for i in range(self.start_page_number, self.end_page_number):
                  self.data['page'] = i
                  if i == self.current_page:
      
                      page_html += f'<li class="active"><a href="?{self.data.urlencode()}">{i}</a></li>'
                  else:
                      page_html += f'<li><a href="?{self.data.urlencode()}">{i}</a></li>'
              self.data['page'] = self.current_page + 1
              next_page = f"""
                             <li>
                                   <a href="?{self.data.urlencode()}" aria-label="Next">
                                     <span aria-hidden="true">&raquo;</span>
                                   </a>
                                 </li>
                 """
              page_html += next_page
              self.data['page'] = self.total_page_count
              last_page = f"""
                                 <li>
                                   <a href="?{self.data.urlencode()}" aria-label="Previous">
                                     <span aria-hidden="true">尾页</span>
                                   </a>
                                 </li>"""
              page_html += last_page
      
              page_html += """
      
                               </ul>
                             </nav>
                         """
              return mark_safe(page_html)
      
      

    views

    • entry_obj = models.Enrollment.objects.all()
      page = request.GET.get("page")	#当前页面
      
      total_count = entry_obj.count()	#总数据数
      
      per_page_count = 10				#每页显示数据条数
      
      per_page_page = 7				#每页页码显示
      
      data = copy.copy(request.GET)	#可编辑Queryset对象
      
      page_obj = Paging(total_count, per_page_count, per_page_page, page, data)					  #实例化分页对象,参数是位置参数,一一对应
      
      entry_obj=entry_obj[
      page_obj.start_data_number:page_obj.end_data_number]
      								#。。。。
      
      page_html = page_obj.paging_html #生成分页HTML标签
      

    bootstrap版分页器

    class Pagination(object):
    """自定义分页(Bootstrap版)"""
    def __init__(self, current_page, total_count, base_url, per_page=10, max_show=11):
        """
        :param current_page: 当前请求的页码
        :param total_count: 总数据量
        :param base_url: 请求的URL
        :param per_page: 每页显示的数据量,默认值为10
        :param max_show: 页面上最多显示多少个页码,默认值为11
        """
        try:
            self.current_page = int(current_page)
        except Exception as e:
            # 取不到或者页码数不是数字都默认展示第1页
            self.current_page = 1
        # 定义每页显示多少条数据
        self.per_page = per_page
        # 计算出总页码数
        total_page, more = divmod(total_count, per_page)
        if more:
            total_page += 1
        self.total_page = total_page
        # 定义页面上最多显示多少页码(为了左右对称,一般设为奇数)
        self.max_show = max_show
        self.half_show = max_show // 2
        self.base_url = base_url
    
    @property
    def start(self):
        return (self.current_page-1) * self.per_page
    
    @property
    def end(self):
        return self.current_page * self.per_page
    
    def page_html(self):
        # 计算一下页面显示的页码范围
        if self.total_page <= self.max_show:  # 总页码数小于最大显示页码数
            page_start = 1
            page_end = self.total_page
        elif self.current_page + self.half_show >= self.total_page:  # 右边越界
            page_end = self.total_page
            page_start = self.total_page - self.max_show
        elif self.current_page - self.half_show <= 1:  # 左边越界
            page_start = 1
            page_end = self.max_show
        else:  # 正常页码区间
            page_start = self.current_page - self.half_show
            page_end = self.current_page + self.half_show
        # 生成页面上显示的页码
        page_html_list = []
        page_html_list.append('<nav aria-label="Page navigation"><ul class="pagination">')
        # 加首页
        first_li = '<li><a href="{}?page=1">首页</a></li>'.format(self.base_url)
        page_html_list.append(first_li)
        # 加上一页
        if self.current_page == 1:
            prev_li = '<li><a href="#"><span aria-hidden="true">&laquo;</span></a></li>'
        else:
            prev_li = '<li><a href="{}?page={}"><span aria-hidden="true">&laquo;</span></a></li>'.format(
                self.base_url, self.current_page - 1)
        page_html_list.append(prev_li)
        for i in range(page_start, page_end + 1):
            if i == self.current_page:
                li_tag = '<li class="active"><a href="{0}?page={1}">{1}</a></li>'.format(self.base_url, i)
            else:
                li_tag = '<li><a href="{0}?page={1}">{1}</a></li>'.format(self.base_url, i)
            page_html_list.append(li_tag)
        # 加下一页
        if self.current_page == self.total_page:
            next_li = '<li><a href="#"><span aria-hidden="true">&raquo;</span></a></li>'
        else:
            next_li = '<li><a href="{}?page={}"><span aria-hidden="true">&raquo;</span></a></li>'.format(
                self.base_url, self.current_page + 1)
        page_html_list.append(next_li)
        # 加尾页
        page_end_li = '<li><a href="{}?page={}">尾页</a></li>'.format(self.base_url, self.total_page)
        page_html_list.append(page_end_li)
        page_html_list.append('</ul></nav>')
        return "".join(page_html_list)
    

    使用示例

    def publisher_list(request):
    # 从URL中取当前访问的页码数
    current_page = int(request.GET.get('page'))
    # 比len(models.Publisher.objects.all())更高效
    total_count = models.Publisher.objects.count()
    page_obj = Pagination(current_page, total_count, request.path_info)
    data = models.Publisher.objects.all()[page_obj.start:page_obj.end]
    page_html = page_obj.page_html()
    return render(request, "publisher_list.html", {"publisher_list": data, "page_html": page_html})
    希望你眼眸有星辰,心中有山海,从此以梦为马,不负韶华
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  • 原文地址:https://www.cnblogs.com/daviddd/p/12053569.html
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