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  • Django 学习组件分页器与自定制分页器

     

    一.Django 分页器

    1.django的分页器基础版

    (1)首先是基础数据分别为

    from django.db import models
    
    
    # Create your models here.
    class Book(models.Model):
        title = models.CharField(max_length=32)
        price = models.DecimalField(max_digits=5, decimal_places=2)
    models.py
    from django.contrib import admin
    from django.urls import path
    from app01 import views
    urlpatterns = [
        path('admin/', admin.site.urls),
        path('book/', views.Book.as_view())
    ]
    urls.py

    (2)基础版的视图函数

    from django.shortcuts import render, redirect
    from django.views import View                 # 导入view
    from app01 import models                      # 导入模型
    from django.core.paginator import Paginator   # 导入django分页器
    import random
    
    
    # Create your views here.
    class Book(View):
        def get(self, request):
            # 法二:批量增加测试数据  效率块
            # book_list = []
            # for i in range(1, 101):
            #     # models.Book.objects.create(title="book_%s" % i, price=random.randint(20, 300))  # 法一:执行效率低
            #     book_list.append(models.Book(title="book_%s" % i, price=random.randint(20, 300)))
            # models.Book.objects.bulk_create(book_list)  # 批量新增数据
            # 分页器的基本语法
            # book_list = models.Book.objects.all()
            # print(book_list)  # QuerySet book对象
            # # 实例化分页对象
            # paginator = Paginator(book_list, 10)
            # print("count:", paginator.count)               # 数据的总数
            # print("num_pages:", paginator.num_pages)       # 分页的总页数
            # print("page_range:",paginator.page_range)     # 页数的范围列表
            #
            # page1 = paginator.get_page(1)                  # 获取第一页的所有数据
            # for i in page1:                                # 遍历第一页的所有数据对象
            #     print(i)
            # print(page1.object_list)                       # 第一页的所用数据
            # page2 = paginator.get_page(2)                  # 获取第二页的所有数据
            # print(page2.has_next())                        # 是否有下一页
            # print(page2.next_page_number())                # 下一页的页码
            # print(page2.has_previous())                    # 是否有上一页
            # print(page2.previous_page_number())            # 上一页的页码
            # 当get不存在的页数或者填写其他类型的数据时会报错
            # page=paginator.page(22)                       # error:EmptyPage
            # page=paginator.page("z")                      # error:PageNotAnInteger
    
    
            # ############# django分页器的基本使用 ##################
            book_list = models.Book.objects.all()
            paginator = Paginator(book_list, 10)            # 每页分的数量(数据量)
    
            current_page = int(
                request.GET.get("page") if request.GET.get("page") and request.GET.get("page").isdigit() else 1)  # 获取页码
            page = paginator.get_page(current_page)  # 获取当前页码的所有数据
    
            return render(request, "book.html", {"paginator": paginator, "page": page, "current_page": current_page})
    
        def post(self, request):
            return redirect("/book/")
    views.py

    (3)最后是模板内容

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css"
              integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
    </head>
    <body>
    <h2>图书列表</h2>
    <ul>
        {% for book in page %}
            <li>{{ book.title }} --- {{ book.price }}</li>
        {% endfor %}
    </ul>
    <nav aria-label="Page navigation">
        <ul class="pagination">
            <li><a href="?page=1">首页</a></li>
            {% if page.has_previous %}
                <li><a href="?page={{ page.previous_page_number }}">上一页</a></li>
            {% else %}
                <li class="disabled"><a href="javascript:void(0);">上一页</a></li>
            {% endif %}
            {% for num in paginator.page_range %}
                {% if current_page == num %}
                    <li class="active"><a href="?page={{ num }}">{{ num }}</a></li>
                {% else %}
                    <li><a href="?page={{ num }}">{{ num }}</a></li>
                {% endif %}
            {% endfor %}
            {% if page.has_next %}
                <li><a href="?page={{ page.next_page_number }}">下一页</a></li>
            {% else %}
                <li class="disabled"><a href="javascript:void(0);">下一页</a></li>
            {% endif %}
            <li><a href="?page={{ paginator.num_pages }}">尾页</a></li>
        </ul>
    </nav>
    
    
    </body>
    </html>
    book.html

    2.进阶版分页器

    上面的示例,看似已经完成了分页的效果,但是,如果我们把每页显示的数量改小一点看一下效果。

    显然这样不是我们想要的

    (1)进阶版视图函数

    from django.shortcuts import render, redirect
    from django.views import View  # 导入view
    from app01 import models  # 导入模型
    from django.core.paginator import Paginator  # 导入django分页器
    import random
    
    
    # Create your views here.
    class Book(View):
        def get(self, request):
            # ############# django分页器的基本使用进阶版 ##################
            # 分页器的基本语法
            book_list = models.Book.objects.all()
    
            # 示例分页器对象
            paginator = Paginator(book_list, 2)      # 每页显示数据的数量
            current_page = int(
                request.GET.get("page") if request.GET.get("page") and request.GET.get("page").isdigit() else 1)
            # 获取页码
            page = paginator.get_page(current_page)  # 获取当前页码的所有数据
            # 默认按照11个页码展示
    
            if paginator.num_pages > 11:
                if current_page - 5 < 1:
                    page_range = range(1, 12)
                elif current_page + 5 > paginator.num_pages:
                    page_range = range(paginator.num_pages - 10, paginator.num_pages + 1)
                else:
                    page_range = range(current_page - 5, current_page + 6)
    
            else:
                page_range = paginator.page_range
    
            # 默认是10个页码
            # if paginator.num_pages > 10:
            #     if current_page - 4 < 1:
            #         page_range = range(1, 11)
            #     elif current_page + 5 > paginator.num_pages:
            #         page_range = range(paginator.num_pages - 9, paginator.num_pages + 1)
            #     else:
            #         page_range = range(current_page - 5, current_page + 5)
            #
            # else:
            #     page_range = paginator.page_range
            return render(request, "book.html", {
                'paginator': paginator, "current_page": current_page, "page": page, "page_range": page_range
            })
    views.py

    (2)模板内容

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css"
              integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
    </head>
    <body>
    <h2>图书列表</h2>
    <ul>
    
    {#    {% for book in page %}#}
    {#        <li>{{ book.title }} --- {{ book.price }}</li>#}
    {#    {% endfor %}#}
        {% for p in page %}
            <li>{{ p }}</li>
        {% endfor %}
    </ul>
    <nav aria-label="Page navigation">
        <ul class="pagination">
            {#        首页#}
            <li>
                <a href="?page=1" aria-label="Previous">
                    <span aria-hidden="true">首页</span>
                </a>
            </li>
            {#  上一页#}
            {% if page.has_previous %}
                <li>
                    <a href="?page={{ page.previous_page_number }}" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>
            {% else %}
                <li class="disabled">
                    <a href="javascript:void(0);" aria-label="Previous">
                        <span aria-hidden="true">&laquo;</span>
                    </a>
                </li>
            {% endif %}
    
            {#        页码#}
    {#        {% for num in paginator.page_range %}#}
            {% for num in page_range %}
                {% if num == current_page %}
                    <li class="active"><a href="?page={{ num }}">{{ num }}</a></li>
                {% else %}
                    <li><a href="?page={{ num }}">{{ num }}</a></li>
                {% endif %}
    
            {% endfor %}
    
            {#    下一页#}
            {% if page.has_next %}
                <li>
                    <a href="?page={{ page.next_page_number }}" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
            {% else %}
                <li class="disabled">
                    <a href="javascript:void(0);" aria-label="Next">
                        <span aria-hidden="true">&raquo;</span>
                    </a>
                </li>
            {% endif %}
    
            {#    尾页#}
            <li>
                <a href="?page={{ paginator.num_pages }}" aria-label="Next">
                    <span aria-hidden="true">尾页</span>
                </a>
            </li>
        </ul>
    </nav>
    </body>
    </html>
    book.html

    显示的效果为:

     3.页码数设置奇数偶数优化版

    (1)视图函数

    from django.shortcuts import render
    from django.views import View  # 导入view
    from app01 import models  # 导入模型
    from django.core.paginator import Paginator  # 导入django分页器
    import math
    # Create your views here.
    # 页码数设置奇数偶数优化版:只要设置page_num 页码即可,奇数偶数都兼容
    class Book(View):
        def get(self, request):
            # ############# django分页器的基本使用进阶版 ##################
            # 分页器的基本语法
            book_list = models.Book.objects.all()
    
            # 示例分页器对象
            paginator = Paginator(book_list, 2)      # 每页显示数据的数量
            current_page = int(
                request.GET.get("page") if request.GET.get("page") and request.GET.get("page").isdigit() else 1)
            # 获取页码
            page = paginator.get_page(current_page)  # 获取当前页码的所有数据
            page_num = 11    # 设置页码个数,设置需要的个数可以为奇数,偶数
            if paginator.num_pages > page_num:
    
                if current_page - math.floor(page_num/2) < 1:
                    page_range = range(1, page_num+1)
                elif current_page + math.ceil((page_num-1)/2) > paginator.num_pages:
                    page_range = range(paginator.num_pages - (page_num-1), paginator.num_pages + 1)
                else:
                    page_range = range(current_page - math.ceil((page_num-1)/2), current_page + math.floor((page_num+1)/2))
            else:
                page_range = paginator.page_range
    
            return render(request, "book.html", {
                'paginator': paginator, "current_page": current_page, "page": page, "page_range": page_range
            })
    views.py

    (2)模板内容

    模板内容同上2的模板内容

    效果图:奇数

    效果图:偶数

     二.自定制分页器

    前提是已经在一上面的基础上,对视图和模板进行修改

    1. 自定制分页器

    (1)自定致分页器类

    class Paginator:
        def __init__(self, current_page, all_count, per_page=10, max_page_num=11):
            """
            封装分页相关数据
            :param current_page:  当前页码
            :param all_count:  数据库中的数据总条数
            :param per_page:   每个页面显示的数据条数
            :param max_page_num:  最多显示的页码个数
            :param num_pages:  通过总条数/每个页面显示的条数,求出总页数
            """
            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 = per_page
    
            # 计算总页数
            num_pages, temp = divmod(all_count, per_page)
            if temp:
                num_pages += 1
            self.num_pages = num_pages
    
            self.max_page_num = max_page_num  # 11
            self.page_count_half = int((self.max_page_num - 1) / 2)  # 5
            """
            self.num_pages=100
            per_page=8
    
            current_page =1     [0:8]
            current_page =2     [8:16]
            current_page =3     [16:24]
                                [(current_page-1)*per_page:current_page*per_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):
            # 如果总页数小于self.max_page_num(最多显示的页码个数)
            if self.num_pages <= self.max_page_num:
                page_start = 1
                page_end = self.num_pages + 1
            else:
                # 如果当前页码<=页面上最多显示11/2个页码时
                if self.current_page <= self.page_count_half:
                    page_start = 1
                    page_end = self.max_page_num + 1
                # 如果当前页码+最多显示11/2 大于 总页数时
                elif self.current_page + self.page_count_half > self.num_pages:
                    page_start = self.num_pages - self.max_page_num + 1
                    page_end = self.num_pages + 1
                else:
                    page_start = self.current_page - self.page_count_half
                    page_end = self.current_page + self.page_count_half + 1
    
            page_html_list = []
    
            # 首页
            first_page = '<nav aria-label="Page navigation"><ul class="pagination"><li><a href="?page=1">首页</a></li>'
            page_html_list.append(first_page)
    
            # 上一页
            if self.current_page <= 1:
                prev_page = '<li class="disabled"><a href="javascript:void(0);">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)
    
            # 显示页码
            for i in range(page_start, page_end):
                if self.current_page == i:
                    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)
    
            # 下一页
            if self.current_page >= self.num_pages:
                next_page = '<li class="disabled"><a href="javascript:void(0);">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)
    
            # 尾页
            last_page = '<li><a href="?page=%s">尾页</a></li></ul></nav>' % self.num_pages
            page_html_list.append(last_page)
    
            return "".join(page_html_list)
    View Code

    (2)视图函数

    from django.shortcuts import render, redirect
    from django.views import View  # 导入view
    from app01 import models  # 导入模型
    from app01.page import Paginator # 导入自定制的分页器
    
    class Book(View):
        def get(self, request):
            book_list = models.Book.objects.all()
            current_page = request.GET.get('page')
        #                     当前页数       数据总数            每页数据量  分页量
            paginator = Paginator(current_page, book_list.count(), 6, 11)
            book_list = book_list[paginator.start: paginator.end]
    
            return render(request, "book.html",
                          {"book_list": book_list, "paginator": paginator, "current_page": current_page})
    views.py

    (3)模板函数

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
        <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css"
              integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
    </head>
    <body>
    <h2>图书列表</h2>
    <ul>
        {% for book in book_list %}
            <li>{{ book.title }} --- {{ book.price }}</li>
        {% endfor %}
    </ul>
    
    {{ paginator.page_html|safe }}
    
    </body>
    </html>
    book.html

    效果图:

    2.终极版本分页器

    为什么需要终极版本呢,因为上面都还有些缺陷,那就是如果请求头还有其他数据,换页后会消失。

    (1)终极版自定义分页类

    class Paginator:
        def __init__(self, request, current_page, all_count, per_page=10, max_page_num=13):
            """
            封装分页相关数据
            :param current_page:  当前页码
            :param all_count:  数据库中的数据总条数
            :param per_page:   每个页面显示的数据条数
            :param max_page_num:  最多显示的页码个数
            :param num_pages:  通过总条数/每个页面显示的条数,求出总页数
            """
            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 = per_page
    
            # 计算总页数
            num_pages, temp = divmod(all_count, per_page)
            if temp:
                num_pages += 1
            self.num_pages = num_pages
    
            self.max_page_num = max_page_num  # 11
            self.page_count_half = int((self.max_page_num - 1) / 2)  # 5
    
            import copy
            self.url_args = copy.deepcopy(request.GET)
            print(self.url_args.urlencode())
    
    
            """
            self.num_pages=100
            per_page=8
    
            current_page =1     [0:8]
            current_page =2     [8:16]
            current_page =3     [16:24]
                                [(current_page-1)*per_page:current_page*per_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):
            # 如果总页数小于self.max_page_num(最多显示的页码个数)
            if self.num_pages <= self.max_page_num:
                page_start = 1
                page_end = self.num_pages + 1
            else:
                # 如果当前页码<=页面上最多显示11/2个页码时
                if self.current_page <= self.page_count_half:
                    page_start = 1
                    page_end = self.max_page_num + 1
                # 如果当前页码+最多显示11/2 大于 总页数时
                elif self.current_page + self.page_count_half > self.num_pages:
                    page_start = self.num_pages - self.max_page_num + 1
                    page_end = self.num_pages + 1
                else:
                    page_start = self.current_page - self.page_count_half
                    page_end = self.current_page + self.page_count_half + 1
    
            page_html_list = []
    
            # 首页
            self.url_args['page'] = 1
            first_page = '<nav aria-label="Page navigation"><ul class="pagination"><li><a href="?%s">首页</a></li>' % (self.url_args.urlencode())
            page_html_list.append(first_page)
    
            # 上一页
            if self.current_page <= 1:
                prev_page = '<li class="disabled"><a href="javascript:void(0);">上一页</a></li>'
            else:
                self.url_args['page'] = self.current_page - 1
                prev_page = '<li><a href="?%s">上一页</a></li>' % (self.url_args.urlencode(), )
            page_html_list.append(prev_page)
    
            # 显示页码
            for i in range(page_start, page_end):
                self.url_args['page'] = i
                if self.current_page == i:
                    temp = '<li class="active"><a href="?%s">%s</a></li>' % (self.url_args.urlencode(), i)
                else:
                    temp = '<li><a href="?%s">%s</a></li>' % (self.url_args.urlencode(), i)
                page_html_list.append(temp)
    
            # 下一页
            if self.current_page >= self.num_pages:
                next_page = '<li class="disabled"><a href="javascript:void(0);">下一页</a></li>'
            else:
                self.url_args['page'] = self.current_page + 1
                next_page = '<li><a href="?%s">下一页</a></li>' % (self.url_args.urlencode(), )
            page_html_list.append(next_page)
    
            # 尾页
            self.url_args['page'] = self.num_pages
            last_page = '<li><a href="?%s">尾页</a></li></ul></nav>' % self.url_args.urlencode()
            page_html_list.append(last_page)
    
            return "".join(page_html_list)
    page.py

    (2)视图函数

    from django.shortcuts import render, redirect
    from django.views import View  # 导入view
    from app01 import models  # 导入模型
    from app01.page import Paginator # 导入自定制的分页器
    class Book(View):
        def get(self, request):
            book_list = models.Book.objects.all()
            current_page = request.GET.get('page')
            paginator = Paginator(request, current_page, book_list.count(), 6, 11)
            book_list = book_list[paginator.start: paginator.end]
    
            return render(request, "book.html", {"book_list": book_list, "paginator": paginator, "current_page": current_page})
    views.py

    (3)模板函数

    模板函数同上即可

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  • 原文地址:https://www.cnblogs.com/hszstudypy/p/11208321.html
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