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  • Django(十四)分页器(paginator)及自定义分页D

    http://www.mamicode.com/info-detail-1724597.html

    http://www.cnblogs.com/wupeiqi/articles/5246483.html

    分页组件
        - Django内置分页
            - Paginator、 Page   
            - 页面:include
        
        - 扩展Django的内置分页
            - CustomPaginator(Paginator)
        传入:
            - 所有数据 
            - 当前页
            - 每页显示30条
            - 最多页面7个
        
        - 自定义分页
        传入:
            - 所有数据的个数
            - 当前页
            - 每页显示30条
            - 最多页面7个

    Django内置分页

    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})
    
    views.py
    views
    <!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>
    
    Html
    html

    扩展内置分页

    from django.shortcuts import render
    from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
    
    
    class CustomPaginator(Paginator):
        def __init__(self, current_page, max_pager_num, *args, **kwargs):
            """
            :param current_page: 当前页
            :param max_pager_num:最多显示的页码个数
            :param args:
            :param kwargs:
            :return:
            """
            self.current_page = int(current_page)
            self.max_pager_num = max_pager_num
            super(CustomPaginator, self).__init__(*args, **kwargs)
    
        def page_num_range(self):
            # 当前页面
            # self.current_page
            # 总页数
            # self.num_pages
            # 最多显示的页码个数
            # self.max_pager_num
            print(1)
            if self.num_pages < self.max_pager_num:
                return range(1, self.num_pages + 1)
            print(2)
            part = int(self.max_pager_num / 2)
            if self.current_page - part < 1:
                return range(1, self.max_pager_num + 1)
            print(3)
            if self.current_page + part > self.num_pages:
                return range(self.num_pages + 1 - self.max_pager_num, self.num_pages + 1)
            print(4)
            return range(self.current_page - part, self.current_page + part + 1)
    
    
    L = []
    for i in range(999):
        L.append(i)
    
    def index(request):
        current_page = request.GET.get('p')
        paginator = CustomPaginator(current_page, 11, 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})
    Views.py
    <!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 %}
    
        {% for i in posts.paginator.page_num_range %}
            <a href="?p={{ i }}">{{ i }}</a>
        {% endfor %}
    
        {% if posts.has_next %}
            <a href="?p={{ posts.next_page_number }}">Next</a>
        {% endif %}
    </span>
    
    <span class="current">
    Page {{ posts.number }} of {{ posts.paginator.num_pages }}.
    </span>
    
    </div>
    </body>
    </html>
    扩展内置分页:Html

     使用模板include

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
    </head>
    <body>
    
    <ul>
        {% for row in posts.object_list %}
            <li>{{ row.name }}-{{ row.age }}</li>
        {% endfor %}
    </ul>
    {% include 'include/pager.html' %}
    </body>
    </html>
    index
    {% if posts.has_previous %}
        <a href="/index?p={{ posts.previous_page_number }}">up</a>
        {% else %}
        <a href="#">up</a>
    {% endif %}
    
    {% for i in posts.paginator.pager_num_range %}
        {% if i == posts.number  %}
            <a style="font-size: 30px;" href="/index?p={{ i }}">{{ i }}</a>
        {% else %}
            <a href="/index?p={{ i }}">{{ i }}</a>
        {% endif %}
    {% endfor %}
    
    {% if posts.has_next %}
        <a href="/index?p={{ posts.next_page_number }}">down</a>
        {% else %}
        <a href="#">down</a>
    {% endif %}
    
    <span>
        {{ posts.number }}/{{ posts.paginator.num_pages }}
    </span>
    pager.html

    自定义分页

    分页功能在每个网站都是必要的,对于分页来说,其实就是根据用户的输入计算出应该在数据库表中的起始位置。

    1、设定每页显示数据条数

    2、用户输入页码(第一页、第二页...)

    3、根据设定的每页显示条数和当前页码,计算出需要取数据表的起始位置

    4、在数据表中根据起始位置取值,页面上输出数据


    需求又来了,需要在页面上显示分页的页面。如:[上一页][1][2][3][4][5][下一页]

    1、设定每页显示数据条数

    2、用户输入页码(第一页、第二页...)

    3、设定显示多少页号

    4、获取当前数据总条数

    5、根据设定显示多少页号和数据总条数计算出,总页数

    6、根据设定的每页显示条数和当前页码,计算出需要取数据表的起始位置

    7、在数据表中根据起始位置取值,页面上输出数据

    8、输出分页html,如:[上一页][1][2][3][4][5][下一页]

    from django.shortcuts import render
    from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
    
    
    USER_LIST = []
    for i in range(1,666):
        temp = {'name':'root'+str(i), 'age':i}
        USER_LIST.append(temp)
    
    def index2(request):
        from app01.pager import Pagination
        current_page = request.GET.get('p')
        page_obj = Pagination(666,current_page)
    
        data_list = USER_LIST[page_obj.start():page_obj.end()]
        return render(request,'index2.html',{'data':data_list,'page_obj':page_obj})
    views.py
    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <link rel="stylesheet" href="/static/bootstrap-3.3.7-dist/css/bootstrap.css" />
    </head>
    <body>
        <ul>
            {% for row in data %}
                <li>{{ row.name }}-{{ row.age }}</li>
            {% endfor %}
        </ul>
        {% for i in page_obj.pager_num_range %}
            <a href="/index2.html?p={{ i }}">{{ i }}</a>
        {% endfor %}
        <hr/>
    
        <ul class="pagination pagination-sm">
            {{ page_obj.page_str|safe }}
          </ul>
        <div style="height: 300px;"></div>
    </body>
    </html>
    index2
    class Pagination(object):
        def __init__(self,totalCount,currentPage,perPageItemNum=10,maxPageNum=7):
            # 数据总个数
            self.total_count = totalCount
            # 当前页
            try:
                v = int(currentPage)
                if v <= 0:
                   v = 1
                self.current_page = v
            except Exception as e:
                self.current_page = 1
            # 每页显示的行数
            self.per_page_item_num = perPageItemNum
            # 最多显示页面
            self.max_page_num = maxPageNum
    
        def start(self):
            return (self.current_page-1) * self.per_page_item_num
    
        def end(self):
            return self.current_page * self.per_page_item_num
        @property
        def num_pages(self):
            """
            总页数
            :return:
            """
            # 666
            # 10
            a,b = divmod(self.total_count,self.per_page_item_num)
            if b == 0:
                return a
            return a+1
    
        def pager_num_range(self):
            # self.num_pages()
            # self.num_pages
            # 当前页
            #self.current_page
            # 最多显示的页码数量 11
            #self.per_pager_num
            # 总页数
            # self.num_pages
            if self.num_pages < self.max_page_num:
                return range(1,self.num_pages+1)
            # 总页数特别多 5
            part = int(self.max_page_num/2)
            if self.current_page <= part:
                return range(1,self.max_page_num+1)
            if (self.current_page + part) > self.num_pages:
                return range(self.num_pages-self.max_page_num+1,self.num_pages+1)
            return range(self.current_page-part,self.current_page+part+1)
    
        def page_str(self):
            page_list = []
    
            first = "<li><a href='/index2.html?p=1'>首页</a></li>"
            page_list.append(first)
    
            if self.current_page == 1:
                prev = "<li><a href='#'>上一页</a></li>"
            else:
                prev = "<li><a href='/index2.html?p=%s'>上一页</a></li>" %(self.current_page-1,)
            page_list.append(prev)
            for i in self.pager_num_range():
                if i == self.current_page:
                    temp = "<li class='active'><a href='/index2.html?p=%s'>%s</a></li>" %(i,i)
                else:
                    temp = "<li><a href='/index2.html?p=%s'>%s</a></li>" % (i, i)
                page_list.append(temp)
    
            if self.current_page == self.num_pages:
                nex = "<li><a href='#'>下一页</a></li>"
            else:
                nex = "<li><a href='/index2.html?p=%s'>下一页</a></li>" % (self.current_page + 1,)
            page_list.append(nex)
    
            last = "<li><a href='/index2.html?p=%s'>尾页</a></li>" %(self.num_pages,)
            page_list.append(last)
    
            return ''.join(page_list)
    pager.py

    总结,分页时需要做三件事:

    • 创建处理分页数据的类
    • 根据分页数据获取数据
    • 输出分页HTML,即:[上一页][1][2][3][4][5][下一页]
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  • 原文地址:https://www.cnblogs.com/xiangtingshen/p/10652953.html
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