Django（十四）分页器（paginator）及自定义分页D

时间：2021-06-16 12:43:32

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:

        """

        #

        #

        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

Django（十四）分页器（paginator）及自定义分页D

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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