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Django - 分页器

时间:2019-02-11 15:35:46      阅读:148      评论:0      收藏:0      [点我收藏+]

标签:rtc   int   就会   最新   文件   lan   request   总数   cross   

 

一.分页器:

 

知识点先览

Paginator:Django分页器
bulk_create:批量插入数据
paginator.count:数据总数,其中paginator是分页器实例化对象
paginator.num_pages:总页数
paginator.page_range:页码的列表
object_list:分页之后的数据列表
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

 

  models.py

from django.db import models

# Create your models here.

class Book(models.Model):

    title = models.CharField(max_length=32)
    price = models.DecimalField(max_digits=8,decimal_places=2)

 

  views.py

# -*- encoding:utf-8 -*-
from django.shortcuts import render

# Create your views here.
from app01.models import Book

from django.core.paginator import Paginator,EmptyPage # 导入分页器

def index(request):

    # 方法不好,每次都要插入数据,需要插入100次
    # for i in range(100):
    #     Book.objects.create(title="book_%s"%i,price=i*i)

    # 批量插入,导入到数据库里 bulk_create
    ‘‘‘
    book_list = []
    for i in range(100):
        book_obj = Book(title="book_%s"%i,price=i*i)
        book_list.append(book_obj)

    Book.objects.bulk_create(book_list)
    ‘‘‘

    book_list = Book.objects.all() # 拿到所有书籍数据

    # 分页器
    paginator = Paginator(book_list,8) # 第一个参数是需要分页的列表,第二个是每页需要展示的数目
    print(paginator.count)  # 数据总数
    print(paginator.num_pages) # 总页数
    print(paginator.page_range) # 页码的列表,总页数+1
    # 100
    # 13
    # range(1, 14)

    page1 = paginator.page(1)  # 第一页的page对象,固定死了

    # 动态显示


    try:
        current_page_num = int(request.GET.get("page", 1))  # get数据是通过?连接的 http://127.0.0.1:8000/index/?page=2
        #做成一个动态的效果。给它个默认值拿第一页,不加1就会返回一个None。当前想要的第几页的数据

        current_page = paginator.page(current_page_num) # 拿到第几页的page对象

        # 显示每一页具体数据的两种方式
        print("object_list",page1.object_list)
        # object_list < QuerySet[ < Book: Book object (1) >, < Book: Book object (2) >, < Book: Book object (3) >,
        # < Book: Book object (4) >, < Book: Book object (5) >, < Book: Book object (6) >, < Book: Book object (7) >,
        # < Book: Book object (8) >] >

        for i in page1:
            print(i)
        # Book object (1)
        # Book object (2)
        # Book object (3)
        # Book object (4)
        # Book object (5)
        # Book object (6)
        # Book object (7)
        # Book object (8)
    except EmptyPage as e:
        current_page = paginator.page(1)

    return render(request,"index.html",locals())

 

  index.html

<!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>
    <p3>index</p3>

  {# 显示当前页面的书籍信息 #}
    <ul>
        {% for book in current_page %}
         <li>{{ book.title }}:{{ book.price }}</li>
        {% endfor %}

    </ul>

    <nav aria-label="Page navigation">  // 分页的页面
        <ul class="pagination">
        {# 无法显示上一页和下一页 #}
{#        <li>#}
{#          <a href="?page={{ current_page_num|add:-1 }}" aria-label="Previous">#} // 上一页:当前页码减一 --> href="?page={{current_page_num|add:-1}}"
{#            <span aria-hidden="true">上一页</span>#}
{#          </a>#}
{#        </li>#}

        {% if current_page.has_previous %} // 判断当前页面是否还有上一页
            <li>
              <a href="?page={{ current_page.previous_page_number }}" aria-label="Previous"> // 获得当前页面上一页的页码
                <span aria-hidden="true">上一页</span>
              </a>
            </li>
        {% else %}
            <li class="disabled">   {# bootstrap设置disabled 不能点击#} // 上一页没数据就不能点击
              <a href="#" aria-label="Previous">
                <span aria-hidden="true">上一页</span>
              </a>
            </li>
        {% endif %}



        {% for item in paginator.page_range %} // item为数字,这里不应该写死 --> page_range
        {#{% for item in page_range %}#}

        {% if current_page_num == item %}  {# 判断当前页码是否和循环的页码一致 bootstrap设置的active会显示深色, #}
            <li class="active"><a href="?page={{ item }}">{{ item }}</a></li>
        {% else %}
            <li><a href="?page={{ item }}">{{ item }}</a></li>
        {% endif %}

        {% endfor %}

{#        <li>#}
{#          <a href="?page={{ current_page_num|add:1 }}" aria-label="Next">#}
{#            <span aria-hidden="true">下一页</span>#}
{#          </a>#}
{#        </li>#}

        {% if current_page.has_next %}  // 判断当前页面是否还有下一页
            <li>
              <a href="?page={{ current_page.next_page_number }}" aria-label="Next"> // 获得下一页页面的页码
                <span aria-hidden="true">下一页</span>
              </a>
            </li>
        {% else %}
            <li class="disabled">
              <a href="#" aria-label="Previous">
                <span aria-hidden="true">下一页</span>
              </a>
            </li>
        {% endif %}

        </ul>
    </nav>

</body>
</html>

 

 

改进版:

  views.py

# -*- encoding:utf-8 -*-
from django.shortcuts import render

# Create your views here.
from app01.models import Book

from django.core.paginator import Paginator,EmptyPage # 导入分页器

def index(request):

    # 方法不好,每次都要插入数据,需要插入100次
    # for i in range(100):
    #     Book.objects.create(title="book_%s"%i,price=i*i)

    # 批量插入 bulk_create
    ‘‘‘
    book_list = []
    for i in range(100):
        book_obj = Book(title="book_%s"%i,price=i*i)
        book_list.append(book_obj)

    Book.objects.bulk_create(book_list)
    ‘‘‘

    book_list = Book.objects.all()

    # 分页器
    paginator = Paginator(book_list,3) # 第一个参数是需要分页的列表,第二个是每页需要展示的数目
    print(paginator.count)  # 数据总数
    print(paginator.num_pages) # 总页数
    print(paginator.page_range) # 页码的列表,总页数+1
    # 100
    # 13
    # range(1, 14)

    page1 = paginator.page(1)  # 第一页的page对象,固定死了

    # 动态显示

    current_page_num = int(request.GET.get("page", 1))  # get数据是通过?连接的 http://127.0.0.1:8000/index/?page=2

    # 固定页码数居中

    if paginator.num_pages > 11:
        if current_page_num - 5 < 1:     ## 点1,2,3,4,5,6页码不动,点7开始左五右五,点倒数五个页面不动
            page_range = range(1,12)
        elif current_page_num + 6 > paginator.num_pages:
            page_range = range(paginator.num_pages-10,paginator.num_pages+1)
        else:
            page_range = range(current_page_num-5,current_page_num+6)
    else:
        page_range = paginator.page_range

    try:
        current_page = paginator.page(current_page_num)

        # 显示每一页具体数据的两种方式
        print("object_list",page1.object_list)
        # object_list < QuerySet[ < Book: Book object (1) >, < Book: Book object (2) >, < Book: Book object (3) >,
        # < Book: Book object (4) >, < Book: Book object (5) >, < Book: Book object (6) >, < Book: Book object (7) >,
        # < Book: Book object (8) >] >

        for i in page1:
            print(i)
        # Book object (1)
        # Book object (2)
        # Book object (3)
        # Book object (4)
        # Book object (5)
        # Book object (6)
        # Book object (7)
        # Book object (8)
    except EmptyPage as e:
        current_page = paginator.page(1)

    return render(request,"index.html",locals())

 

  index,html

{% for item in page_range %}  不应该写死,其他同上
                {% if current_page_num == item %}
                    <li class="active"><a href="?page={{ item }}">{{ item }}</a></li>
                {% else %}
                    <li><a href="?page={{ item }}">{{ item }}</a></li>
                {% endif %}
            {% endfor %}

Django - 分页器

标签:rtc   int   就会   最新   文件   lan   request   总数   cross   

原文地址:https://www.cnblogs.com/mumupa0824/p/10361854.html

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