Django之分頁

最初的版本

views.py

from django.shortcuts import render, HttpResponse, redirect
from django.utils.safestring import mark_safe

practice_pagination_data = [{'name': 'ward{}'.format(i), 'pwd': 'pwd{}'.format(i)} for i in range(1, 302)]


# 練習分頁

def practice_pagination(request):
    # 當期頁面
    try:
        current_page = int(request.GET.get('page', 1))
        print(current_page)
        if current_page <= 0:
            current_page = 1
    except Exception as e:
        current_page = 1
        print(e)
    # 最多顯示的頁碼數
    max_show = 9
    # 在當前的頁面左右各顯示通常的數據
    half_show = max_show // 2

    # 每頁顯示的數據條數
    per_num = 10

    # 總數據量
    all_count = len(practice_pagination_data)

    # 頁碼總數
    total_num, more = divmod(all_count, per_num)
    # 若是有餘數
    if more:
        total_num += 1
    # 總頁碼數小於最大顯示數：顯示總頁數
    if total_num < max_show:
        page_start = 1
        page_end = total_num
    else:
        # 總頁碼數大於最大顯示數：最多顯示11個
        if current_page <= half_show:
            page_start = 1
            page_end = max_show
        elif current_page + half_show >= total_num:
            page_end = total_num
            page_start = total_num - max_show + 1
        else:
            page_start = current_page - half_show
            page_end = current_page + half_show

    # 存放<li>標籤的列表（目的是爲了將全部的事情在服務端都作好，返回html字符串就ok）
    html_list = []

    # 首頁操做
    first_li = '<li><a href="/practice_pagination/?page=1">首頁</a></li>'
    html_list.append(first_li)

    # 若是已經到了第一頁，再點擊上一頁是不被容許的,
    if current_page == 1:
        prev_li = '<li class="disabled"><a>上一頁</a></li>'
    else:
        prev_li = '<li><a href="/practice_pagination/?page={0}">上一頁</a></li>'.format(current_page - 1)
    html_list.append(prev_li)

    # 將切片範圍內數據展現
    for num in range(page_start, page_end + 1):
        # 若是是當前頁面。將此標籤選中
        if current_page == num:
            li_html = '<li class="active"><a href="/practice_pagination/?page={0}">{0}</a></li>'.format(num)
        else:
            li_html = '<li><a href="/practice_pagination/?page={0}">{0}</a></li>'.format(num)
        html_list.append(li_html)
    # 當前頁面爲最後一頁，不能再點擊下一頁
    if current_page == total_num:
        next_li = '<li class="disabled"><a>下一頁</a></li>'
    else:
        next_li = '<li><a href="practice_pagination"?page={}>下一頁</a></li>'.format(current_page + 1)
    html_list.append(next_li)

    # 尾頁操做
    last_li = '<li><a href="/practice_pagination/?page={}">尾頁</a></li>'.format(total_num)
    html_list.append(last_li)

    # 將列表組成字符串
    html_str = mark_safe(''.join(html_list))

    # 切片的起始值
    start = (current_page - 1) * per_num
    print(start)
    # 切片的終止值
    end = current_page * per_num
    print(end)

    return render(request, 'practice_pagination.html', {
        'data': practice_pagination_data[start:end],
        'html_str': html_str,
    })

 <div class="panel panel-default">
        <div class="panel-heading">用戶信息</div>
        <div class="panel-body">

            <table class="table table-hover table-bordered">
                <thead>
                <tr>
                    <th>序號</th>
                    <th>用戶名</th>
                    <th>密碼</th>
                </tr>
                </thead>
                <tbody>
                {% for user in data %}
                    <tr>
                        <td>{{ forloop.counter }}</td>
                        <td>{{ user.name }}</td>
                        <td>{{ user.pwd }}</td>
                    </tr>
                {% endfor %}
                </tbody>
            </table>
            {#    分頁的模板代碼，用的是Bootstrap分頁樣式    #}
            <nav aria-label="Page navigation" class="navbar-right" style="margin-right: 5px">
                <ul class="pagination">
                    {#   經過後端返回一個字符串（是html字符串，渲染到這裏）  #}
                    {{ html_str }}
                </ul>
            </nav>
        </div>
    </div>

practice_pagination.html

 

進階版--將這個分頁寫爲本身的一個模塊

pagination.py

"""
分頁器
"""

from django.utils.safestring import mark_safe


class Pagination:

    # request 爲request請求， all_count爲全部數據的個數， per_num爲一頁展現多少數據， max_show分多少頁
    def __init__(self, request, all_count, per_num=10, max_show=11):
        # 基本的URL
        self.base_url = request.path_info
        # 當前頁碼
        try:
            self.current_page = int(request.GET.get('page', 1))
            if self.current_page <= 0:
                self.current_page = 1
        except Exception as e:
            self.current_page = 1
            print(e)
        # 最多顯示的頁碼數
        self.max_show = max_show
        half_show = max_show // 2

        # 每頁顯示的數據條數
        self.per_num = per_num
        # 總數據量
        self.all_count = all_count

        # 總頁碼數
        self.total_num, more = divmod(all_count, per_num)
        if more:
            self.total_num += 1

        # 總頁碼數小於最大顯示數：顯示總頁碼數
        if self.total_num <= max_show:
            self.page_start = 1
            self.page_end = self.total_num
        else:
            # 總頁碼數大於最大顯示數：最多顯示11個
            if self.current_page <= half_show:
                self.page_start = 1
                self.page_end = max_show
            elif self.current_page + half_show >= self.total_num:
                self.page_end = self.total_num
                self.page_start = self.total_num - max_show + 1
            else:
                self.page_start = self.current_page - half_show
                self.page_end = self.current_page + half_show

    @property
    def start(self):
        return (self.current_page - 1) * self.per_num

    @property
    def end(self):
        return self.current_page * self.per_num

    @property
    def show_li(self):
        # 存放li標籤的列表
        html_list = []

        first_li = '<li><a href="{}?page=1">首頁</a></li>'.format(self.base_url)
        html_list.append(first_li)

        if self.current_page == 1:
            prev_li = '<li class="disabled"><a><<</a></li>'
        else:
            prev_li = '<li><a href="{1}?page={0}"><<</a></li>'.format(self.current_page - 1, self.base_url)
        html_list.append(prev_li)

        for num in range(self.page_start, self.page_end + 1):
            if self.current_page == num:
                li_html = '<li class="active"><a href="{1}?page={0}">{0}</a></li>'.format(num, self.base_url)
            else:
                li_html = '<li><a href="{1}?page={0}">{0}</a></li>'.format(num, self.base_url)
            html_list.append(li_html)

        if self.current_page == self.total_num:
            next_li = '<li class="disabled"><a>>></a></li>'
        else:
            next_li = '<li><a href="{1}?page={0}">>></a></li>'.format(self.current_page + 1, self.base_url)

        html_list.append(next_li)

        last_li = '<li><a href="{1}?page={0}">尾頁</a></li>'.format(self.total_num, self.base_url)
        html_list.append(last_li)

        return mark_safe(''.join(html_list))

users = [{'name': 'ward{}'.format(i), 'pwd': 'pwd{}'.format(i)} for i in range(1, 302)]

from utils import pagination


def user_list(request):
    page = pagination.Pagination(request, len(users), per_num=13, max_show=8)

    return render(request, 'user_list.html',
                  {
                      "data": users[page.start:page.end],
                      'html_str': page.show_li
                  })

views.py

    <table class="table table-bordered">
        <thead>
        <tr>
            <th>序號</th>
            <th>用戶名</th>
            <th>密碼</th>
        </tr>
        </thead>
        <tbody>
        {% for user in data %}
            <tr>
                <td>{{ forloop.counter }}</td>
                <td>{{ user.name }}</td>
                <td>{{ user.pwd }}</td>
            </tr>
        {% endfor %}

        </tbody>
    </table>

    <nav aria-label="Page navigation" class="navbar-right">
        <ul class="pagination">

            {#            {% for num in total_num %}#}
            {#                <li><a href="/user_list/?page={{ num }}">{{ num }}</a></li>#}
            {#            {% endfor %}#}
            {#            {{ html_str|safe }}#}
            {{ html_str }}
        </ul>
    </nav>

user_list.html