• 第十二章 Django框架——分页组件


    第十二章 Django框架——分页组件

    一、Django的分页器Paginator

    二、视图函数层Views

    三、模板层Templates

    四、补充

    五、自己写逻辑实现分页

    一、Django的分页器Paginator

    如何使用分页器Paginator(how):

    导入模块

    from django.core.paginator import Paginator

    参数

    Paginator对象:    paginator = Paginator(user_list, 10)
    # per_page: 每页显示条目数量
    # count:    数据总个数
    # num_pages:总页数
    # page_range:总页数的索引范围,如: (1,10),(1,200)
    # page:     page对象    
    page对象:page=paginator.page(1)
    # has_next              是否有下一页
    # next_page_number      下一页页码
    # has_previous          是否有上一页
    # previous_page_number  上一页页码
    # object_list           分页之后的数据列表
    # number                当前页
    # paginator             paginator对象

    二、视图函数层Views

    from django.shortcuts import render
    from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
    
    L = []
    for i in range(999):
        L.append(i)
    
    def index(request):
        current_page = request.GET.get('p')
    
        paginator = Paginator(L, 10)
        # per_page: 每页显示条目数量
        # count:    数据总个数
        # num_pages:总页数
        # page_range:总页数的索引范围,如: (1,10),(1,200)
        # page:     page对象
        try:
            posts = paginator.page(current_page)
            # has_next              是否有下一页
            # next_page_number      下一页页码
            # has_previous          是否有上一页
            # previous_page_number  上一页页码
            # object_list           分页之后的数据列表
            # number                当前页
            # paginator             paginator对象
        except PageNotAnInteger:
            posts = paginator.page(1)
        except EmptyPage:
            posts = paginator.page(paginator.num_pages)
        return render(request, 'index.html', {'posts': posts})
    
    内置分页view部分
    View Code

    三、模板层Templates

    <!DOCTYPE html>
    <html>
    <head lang="en">
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
    <ul>
        {% for item in posts %}
            <li>{{ item }}</li>
        {% endfor %}
    </ul>
    
    <div class="pagination">
          <span class="step-links">
            {% if posts.has_previous %}
                <a href="?p={{ posts.previous_page_number }}">Previous</a>
            {% endif %}
              <span class="current">
                Page {{ posts.number }} of {{ posts.paginator.num_pages }}.
              </span>
              {% if posts.has_next %}
                  <a href="?p={{ posts.next_page_number }}">Next</a>
              {% endif %}
          </span>
    
    </div>
    </body>
    </html>
    
    内置分页HTML部分
    View Code

    四、补充

    '''
        显示左5,右5,总共11个页,
    如果总页码大于11
            1.1 if 当前页码减5小于1,要生成1到12的列表(顾头不顾尾,共11个页码)
                page_range=range(1,12)
            1.2 elif 当前页码+5大于总页码,生成当前页码减10,到当前页码加1的列表(顾头不顾尾,共11个页码)
                page_range=range(paginator.num_pages-10,paginator.num_pages+1)
            1.3 else 生成当前页码-5,到当前页码+6的列表
                page_range=range(current_page_num-5,current_page_num+6)
    其它情况,生成的列表就是pageinator的page_range
            page_range=paginator.page_range
    
        '''
    左五右五显示页码的逻辑

    五、自己写逻辑实现分页(转自https://www.cnblogs.com/liwenzhou/p/8343243.html)

    data = []
    
    for i in range(1, 302):
        tmp = {"id": i, "name": "alex-{}".format(i)}
        data.append(tmp)
    
    print(data)
    
    
    def user_list(request):
    
        # user_list = data[0:10]
        # user_list = data[10:20]
        try:
            current_page = int(request.GET.get("page"))
        except Exception as e:
            current_page = 1
    
        per_page = 10
    
        # 数据总条数
        total_count = len(data)
        # 总页码
        total_page, more = divmod(total_count, per_page)
        if more:
            total_page += 1
    
        # 页面最多显示多少个页码
        max_show = 11
        half_show = int((max_show-1)/2)
    
        if current_page <= half_show:
            show_start = 1
            show_end = max_show
        else:
            if current_page + half_show >= total_page:
                show_start = total_page - max_show
                show_end = total_page
            else:
                show_start = current_page - half_show
                show_end = current_page + half_show
    
        # 数据库中获取数据
        data_start = (current_page - 1) * per_page
        data_end = current_page * per_page
    
        user_list = data[data_start:data_end]
    
        # 生成页面上显示的页码
        page_html_list = []
        # 加首页
        first_li = '<li><a href="/user_list/?page=1">首页</a></li>'
        page_html_list.append(first_li)
        # 加上一页
        if current_page == 1:
            prev_li = '<li><a href="#">上一页</a></li>'
        else:
            prev_li = '<li><a href="/user_list/?page={}">上一页</a></li>'.format(current_page - 1)
        page_html_list.append(prev_li)
        for i in range(show_start, show_end+1):
            if i == current_page:
                li_tag = '<li class="active"><a href="/user_list/?page={0}">{0}</a></li>'.format(i)
            else:
                li_tag = '<li><a href="/user_list/?page={0}">{0}</a></li>'.format(i)
            page_html_list.append(li_tag)
    
        # 加下一页
        if current_page == total_page:
            next_li = '<li><a href="#">下一页</a></li>'
        else:
            next_li = '<li><a href="/user_list/?page={}">下一页</a></li>'.format(current_page+1)
        page_html_list.append(next_li)
    
        # 加尾页
        page_end_li = '<li><a href="/user_list/?page={}">尾页</a></li>'.format(total_page)
        page_html_list.append(page_end_li)
    
        page_html = "".join(page_html_list)
    
        return render(request, "user_list.html", {"user_list": user_list, "page_html": page_html})
    
    稳扎稳打版
    普通版
    class Pagination(object):
        def __init__(self, current_page, total_count, base_url, per_page=10, max_show=11):
            """
            :param current_page: 当前页
            :param total_count: 数据库中数据总数
            :param per_page: 每页显示多少条数据
            :param max_show: 最多显示多少页
            """
            try:
                current_page = int(current_page)
            except Exception as e:
                current_page = 1
    
            self.current_page = current_page
            self.total_count = total_count
            self.base_url = base_url
            self.per_page = per_page
            self.max_show = max_show
    
            # 总页码
            total_page, more = divmod(total_count, per_page)
            if more:
                total_page += 1
            
            half_show = int((max_show - 1) / 2)
            self.half_show = half_show
            self.total_page = total_page
    
        @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):
    
            if self.current_page <= self.half_show:
                show_start = 1
                show_end = self.max_show
            else:
                if self.current_page + self.half_show >= self.total_page:
                    show_start = self.total_page - self.max_show
                    show_end = self.total_page
                else:
                    show_start = self.current_page - self.half_show
                    show_end = self.current_page + self.half_show
    
                    # 生成页面上显示的页码
            page_html_list = []
            # 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="#">上一页</a></li>'
            else:
                prev_li = '<li><a href="{0}?page={1}">上一页</a></li>'.format(self.base_url, self.current_page - 1)
            page_html_list.append(prev_li)
            for i in range(show_start, show_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="#">下一页</a></li>'
            else:
                next_li = '<li><a href="{0}?page={1}">下一页</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="{0}?page={1}">尾页</a></li>'.format(self.base_url, self.total_page)
            page_html_list.append(page_end_li)
    
            return "".join(page_html_list)
    
    封装保存版
    封装版
    def user_list(request):
        pager = Pagination(request.GET.get("page"), len(data), request.path_info)
        user_list = data[pager.start:pager.end]
        page_html = pager.page_html()
        return render(request, "user_list.html", {"user_list": user_list, "page_html": page_html})
    封装版使用方法

     

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  • 原文地址:https://www.cnblogs.com/neymargoal/p/9664192.html
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