Django组件(一) Django之分页器

时间:2021-07-24 13:24:40

Django的分页器(paginator)简介

在页面显示分页数据,需要用到Django分页器组件

from django.core.paginator import Paginator

Paginator对象:    paginator = Paginator(user_list, 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
page对象:page=paginator.page(1)
# 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

应用View层

from django.shortcuts import render,HttpResponse

# Create your views here.
from app01.models import *
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger

def index(request):

    '''
    批量导入数据:

    Booklist=[]
    for i in range(100):
        Booklist.append(Book(title="book"+str(i),price=30+i*i))
    Book.objects.bulk_create(Booklist)
    '''

    '''
分页器的使用:

    book_list=Book.objects.all()

    paginator = Paginator(book_list, 10)

    print("count:",paginator.count)           #数据总数
    print("num_pages",paginator.num_pages)    #总页数
    print("page_range",paginator.page_range)  #页码的列表

    page1=paginator.page(1) #第1页的page对象
    for i in page1:         #遍历第1页的所有数据对象
        print(i)

    print(page1.object_list) #第1页的所有数据

    page2=paginator.page(2)

    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

    # 抛错
    #page=paginator.page(12)   # error:EmptyPage

    #page=paginator.page("z")   # error:PageNotAnInteger

    '''

    book_list=Book.objects.all()

    paginator = Paginator(book_list, 10)
    page = request.GET.get('page',1)
    currentPage=int(page)

    try:
        print(page)
        book_list = paginator.page(page)
    except PageNotAnInteger:
        book_list = paginator.page(1)
    except EmptyPage:
        book_list = paginator.page(paginator.num_pages)

    return render(request,"index.html",{"book_list":book_list,"paginator":paginator,"currentPage":currentPage})

模版层 index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css"
    integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
</head>
<body>

<div class="container">

    <h4>分页器</h4>
    <ul>

        {% for book in book_list %}
             <li>{{ book.title }} -----{{ book.price }}</li>
        {% endfor %}

     </ul>

    <ul class="pagination" id="pager">

                 {% if book_list.has_previous %}
                    <li class="previous"><a href="/index/?page={{ book_list.previous_page_number }}">上一页</a></li>
                 {% else %}
                    <li class="previous disabled"><a href="#">上一页</a></li>
                 {% endif %}

                 {% for num in paginator.page_range %}

                     {% if num == currentPage %}
                       <li class="item active"><a href="/index/?page={{ num }}">{{ num }}</a></li>
                     {% else %}
                       <li class="item"><a href="/index/?page={{ num }}">{{ num }}</a></li>

                     {% endif %}
                 {% endfor %}

                 {% if book_list.has_next %}
                    <li class="next"><a href="/index/?page={{ book_list.next_page_number }}">下一页</a></li>
                 {% else %}
                    <li class="next disabled"><a href="#">下一页</a></li>
                 {% endif %}

            </ul>
</div>

</body>
</html>

扩展

'''
    显示左5,右5,总共11个页,
    1 如果总页码大于11
        1.1 if 当前页码减5小于1,要生成1到12的列表(顾头不顾尾,共11个页码)
            page_range=range(1,12)
        1.2 elif 当前页码+5大于总页码,生成当前页码减10,到当前页码加1的列表(顾头不顾尾,共11个页码)
            page_range=range(paginator.num_pages-10,paginator.num_pages+1)
        1.3 else 生成当前页码-5,到当前页码+6的列表
            page_range=range(current_page_num-5,current_page_num+6)
    2 其它情况,生成的列表就是pageinator的page_range
        page_range=paginator.page_range

    '''

  

def index(request):

    book_list=Book.objects.all()

    paginator = Paginator(book_list, 15)
    page = request.GET.get('page',1)
    currentPage=int(page)

    #  如果页数十分多时,换另外一种显示方式

    if paginator.num_pages>11:

        if currentPage-5<1:
            pageRange=range(1,11)
        elif currentPage+5>paginator.num_pages:
            pageRange=range(currentPage-5,paginator.num_pages+1)

        else:
            pageRange=range(currentPage-5,currentPage+5)

    else:
        pageRange=paginator.page_range

    try:
        print(page)
        book_list = paginator.page(page)
    except PageNotAnInteger:
        book_list = paginator.page(1)
    except EmptyPage:
        book_list = paginator.page(paginator.num_pages)

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

  

def page_test(request):
    # book_list=[]
    # for i in range(100):
    #     book=Book(name='book%s'%i,price=10+i,pub_date='2018-09-18',publish_id=1)
    #     book_list.append(book)
    # Book.objects.bulk_create(book_list,10)
    book_list=Book.objects.all()
    # 生成paginator对象,传入书籍列表,每页10条数据
    paginator=Paginator(book_list,3)
    # 总页码数
    print(paginator.num_pages)
    # 页码列表
    print(paginator.page_range)
    # 总数据
    print(paginator.count)
    # 获取页面传来的页码
    current_page=int(request.GET.get('page',1))
    page_range=[]
    # 左5 右5

    # 获取页面传来的页码的page对象
    try:
        page=paginator.page(current_page)
        # print(page.has_next())            #是否有下一页
        # print(page.next_page_number())    #下一页的页码
        # print(page.has_previous())        #是否有上一页
        # print(page.previous_page_number()) #上一页的页码
        # 循环打印出当页对象
        for i in page:
            print(i)
    except Exception as e:
        current_page=1
        page = paginator.page(1)
    if paginator.num_pages>11:
        if current_page+5>paginator.num_pages:
            page_range=range(paginator.num_pages-10,paginator.num_pages+1)
        elif current_page-5<1:
            page_range=range(1,12)
        else:
            page_range=range(current_page-5,current_page+6)
    else:
        page_range=paginator.page_range

    return render(request,'page_test.html',locals())

  

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <link rel="stylesheet" href="/static/bootstrap-3.3.7-dist/css/bootstrap.min.css">
    <title>Title</title>
</head>
<body>

<ul>

    {% for foo in page %}
        <li>{{ foo.name }}</li>

    {% endfor %}

</ul>
<nav aria-label="Page navigation">
    <ul class="pagination">
        {% if page.has_previous %}
            <li>
                <a href="/page_test/?page={{ page.previous_page_number }}" aria-label="Previous">
                    <span aria-hidden="true">上一页</span>
                </a>
            </li>
        {% else %}
            <li class="disabled">
                <a href="#" aria-label="Previous">
                    <span aria-hidden="true">上一页</span>
                </a>
            </li>
        {% endif %}

        {% for foo in page_range %}
            {% if current_page == foo %}
                <li class="active"><a href="/page_test/?page={{ foo }}">{{ foo }}</a></li>
            {% else %}
                <li><a href="/page_test/?page={{ foo }}">{{ foo }}</a></li>
            {% endif %}

        {% endfor %}
        {% if page.has_next %}
            <li>
                <a href="/page_test/?page={{ page.next_page_number }}" aria-label="Next">
                    <span aria-hidden="true">下一页</span>
                </a>
            </li>
        {% else %}
            <li class="disabled">
                <a href="#" aria-label="Next">
                    <span aria-hidden="true">下一页</span>
                </a>
            </li>

        {% endif %}

    </ul>
</nav>

</body>
</html>