Django组件-分页器

1 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

2 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})

3 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>

4 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

    '''
核心逻辑
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())
views
<!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>
模版

使用:

#views.py
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):
    obj_list = Book.objects.all()
    paginator = Paginator(obj_list,9)  # 每页显示行数
    try:
        current_page = int(request.GET.get("page"))  # 防止非数字
    except:
        current_page = 1
    #########################################################
 
    show_page = 11  #默认显示页数
    half = int((show_page - 1) / 2)
    all_pager = paginator.num_pages #总页数
 
    # 如果数据总页数 < 11
    if all_pager < show_page:
        begin = 1
        stop = all_pager + 1
    # 如果数据总页数 > 11
    else:
        # 如果当前页 <=5,永远显示1,11
        if current_page <= half:
            begin = 1
            stop = show_page + 1
        else:
            if current_page + half > all_pager:
                begin = all_pager - show_page + 1
                stop = all_pager + 1
            else:
                begin = current_page - half
                stop = current_page + half + 1
    page_range = range(begin,stop)
    #########################################################
    try:
        obj_list = paginator.page(current_page)
    except PageNotAnInteger:
        obj_list = paginator.page(1)
    except EmptyPage:
        obj_list = paginator.page(paginator.num_pages)
 
    # return render(request,"index.html",locals())
    return render(request, "index.html", {"obj_list": obj_list, "current_page": current_page, "page_range": page_range})
 
'''
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:
    obj_list=Book.objects.all()
    paginator = Paginator(obj_list, 10)     #每页显示10条
 
    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
 
    #显示某一页具体数据的两种方式:
    #方式1
    for i in page1:         #遍历第1页的所有数据对象
        print(i)
 
    #方式2
    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
 
    #当前页
    current_page=int(request.GET.get("page",1))
    obj_list=paginator.page(current_page)
    for i in obj_list:         #遍历当前页的所有数据对象
        print(i)
 
    # 抛错
    #page=paginator.page(12)   # error:EmptyPage
    #page=paginator.page("z")   # error:PageNotAnInteger
 
'''
views.py
<!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 row in obj_list %}
             <li>{{ row.title }} -----{{ row.price }}</li>
        {% endfor %}
     </ul>
 
<nav aria-label="Page navigation">
    <ul class="pagination" id="pager">
                 {% if obj_list.has_previous %}
                    <li class="previous"><a href="?page={{ obj_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 page_range %}
                     {% if num == current_page %}
                       <li class="item active"><a href="?page={{ num }}">{{ num }}</a></li>
                     {% else %}
                       <li class="item"><a href="?page={{ num }}">{{ num }}</a></li>
                     {% endif %}
                 {% endfor %}
 
                 {% if obj_list.has_next %}
                    <li class="next"><a href="?page={{ obj_list.next_page_number }}">下一页</a></li>
                 {% else %}
                    <li class="next disabled"><a href="">下一页</a></li>
                 {% endif %}
     </ul>
</nav>
</div>
 
</body>
</html>
index.html

自定义分页

"""
分页组件
"""


class Pagination(object):
    def __init__(self, current_page, all_count, base_url, query_params, per_page=20, pager_page_count=11):
        """
        分页初始化
        :param current_page: 当前页码
        :param per_page: 每页显示数据条数
        :param all_count: 数据库中总条数
        :param base_url: 基础URL
        :param query_params: QueryDict对象,内部含所有当前URL的原条件
        :param pager_page_count: 页面上最多显示的页码数量
        """
        self.base_url = base_url
        try:
            self.current_page = int(current_page)
            if self.current_page <= 0:
                raise Exception()
        except Exception as e:
            self.current_page = 1
        self.query_params = query_params
        self.per_page = per_page
        self.all_count = all_count
        self.pager_page_count = pager_page_count
        pager_count, b = divmod(all_count, per_page)
        if b != 0:
            pager_count += 1
        self.pager_count = pager_count

        half_pager_page_count = int(pager_page_count / 2)
        self.half_pager_page_count = half_pager_page_count

    @property
    def start(self):
        """
        数据获取值起始索引
        :return:
        """
        return (self.current_page - 1) * self.per_page

    @property
    def end(self):
        """
        数据获取值结束索引
        :return:
        """
        return self.current_page * self.per_page

    def page_html(self):
        """
        生成HTML页码
        :return:
        """
        # 如果数据总页码pager_count<11 pager_page_count
        if self.pager_count < self.pager_page_count:
            pager_start = 1
            pager_end = self.pager_count
        else:
            # 数据页码已经超过11
            # 判断: 如果当前页 <= 5 half_pager_page_count
            if self.current_page <= self.half_pager_page_count:
                pager_start = 1
                pager_end = self.pager_page_count
            else:
                # 如果: 当前页+5 > 总页码
                if (self.current_page + self.half_pager_page_count) > self.pager_count:
                    pager_end = self.pager_count
                    pager_start = self.pager_count - self.pager_page_count + 1
                else:
                    pager_start = self.current_page - self.half_pager_page_count
                    pager_end = self.current_page + self.half_pager_page_count

        page_list = []

        if self.current_page <= 1:
            prev = '<li><a href="#">上一页</a></li>'
        else:
            self.query_params['page'] = self.current_page - 1
            prev = '<li><a href="%s?%s">上一页</a></li>' % (self.base_url, self.query_params.urlencode())
        page_list.append(prev)
        for i in range(pager_start, pager_end + 1):
            self.query_params['page'] = i
            if self.current_page == i:
                tpl = '<li class="active"><a href="%s?%s">%s</a></li>' % (
                    self.base_url, self.query_params.urlencode(), i,)
            else:
                tpl = '<li><a href="%s?%s">%s</a></li>' % (self.base_url, self.query_params.urlencode(), i,)
            page_list.append(tpl)

        if self.current_page >= self.pager_count:
            nex = '<li><a href="#">下一页</a></li>'
        else:
            self.query_params['page'] = self.current_page + 1
            nex = '<li><a href="%s?%s">下一页</a></li>' % (self.base_url, self.query_params.urlencode(),)
        page_list.append(nex)
        page_str = "".join(page_list)
        return page_str
utils/pagination.py
##使用
from django.shortcuts import render, HttpResponse
from utils.pagination import Pagination
def index(request):
    # ==========begin
    all_count = Book.objects.all().count()
    query_params = request.GET.copy()
    query_params._mutable = True

    pager = Pagination(
        current_page=request.GET.get('page'),
        all_count=all_count,
        base_url=request.path_info,
        query_params=query_params,
        per_page=20,
    )
    data_list = Book.objects.all()[pager.start:pager.end]
    # ==========end
    return render(request, 'index.html', {'data_list': data_list, 'pager': pager})


#========模板
"""
<nav>
      <ul class="pagination">
          {{ pager.page_html|safe }}
      </ul>
</nav>
"""
使用

 

posted @ 2019-01-14 00:21  silencio。  阅读(172)  评论(0编辑  收藏  举报