django第11天分页器
分页模块
批量插入数据
book_list = []
#先生成对象
for i in range(100):
book = Book(name = 'book%s'%i,price=10+i)
book_list.append(book)
#操作对象列表,设置一次操作多少条数据
Book.objects.bulk_create(book_list,10)
分页器及其方法
1.导入分页器模块
from django.core.paginator import Paginator
2.生成分页器对象
第一个参数为分页对象列表,第二个参数为一页的数量
paginator = Paginator(book_list,10)
3.分页常用方法
#分页对象的总数
count = paginator.count()
#分成的总页数
num_pages = paginator.num_pages()
#页数的范围
page_range = paginator.page_range
#当前页面数从前台获取
try:
current_page_num = int(request.GET.get('page',1))
except:
current_page_num = 1
#通过当前页数,获得当前页的对象列表(返回给前台迭代显示对象)
current_page = paginator.page(current_page_num)
# 是否有上一页
current_page.has_previous()
# 上一页编码
current_page.previous_page_number()
# 是否有下一页
current_page.has_next()
# 下一页编码
current_page.next_page_number()
基础分页器编写
1.后台
from django.core.paginator import Paginator
def index(request):
#获取图书对象
book_list = Book.objects.all()
#生成分页器对象
paginator = Paginator(book_list,10)
#获取页码范围,以便前台产生分页个数
page_range = paginator.page_range
#从前台获取当前页数,如果是第一次访问就返回第一页
try:
current_page_num = int(request.GET.get('page',1))
except:
current_page_num =1
#通过当前页数,获得current_page,可迭代获得当前页所有对象
current_page = paginator.page(current_page_num)
return render(request,'index.html',locals())
前台
<div class="container-fluid">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<h1>图书详情</h1>
<table class="table">
<tr>
<th>图书名称</th>
<th>图书价格</th>
</tr>
#仅展示当前页数的所有对象
{% for book in current_page %}
<tr>
<td>{{ book.name }}</td>
<td>{{ book.price }}</td>
</tr>
{% endfor %}
</table>
<nav aria-label="Page navigation">
<ul class="pagination">
<li>
#如果存在上一页,当前页码减去1
{% if current_page.has_previous %}
<a href="?page={{ current_page_num|add:-1 }}" aria-label="Previous">
{% else %}
#如果不存在不进行操作
<a href="javascript:void(0)" aria-label="Previous">
{% endif %}
<span aria-hidden="true">上一页</span>
</a>
</li>
#通过页数生成分页项
{% for foo in page_range %}
<li>
<a href="?page={{ foo }}">{{ foo }}</a></li>
<li>
{% endfor %}
<li>
{% if current_page.has_next %}
<a href="?page={{ current_page_num|add:1 }}" aria-label="Next">
{% else %}
<a href="javascript:void(0)" aria-label="Next">
{% endif %}
<span aria-hidden="true">下一页</span>
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
高级分页器编写
当对象个数过多,分的页数过多时,需要将分页器优化,不然会显示一大堆的分页
设计要求:
除了首末页,只显示选中页数,前5页和后5页
前台:
<div class="container-fluid">
<div class="row">
<div class="col-md-6 col-md-offset-3">
<h1>图书详情</h1>
<table class="table">
<tr>
<th>图书名称</th>
<th>图书价格</th>
</tr>
{% for book in current_page %}
<tr>
<td>{{ book.name }}</td>
<td>{{ book.price }}</td>
</tr>
{% endfor %}
</table>
<nav aria-label="Page navigation">
<ul class="pagination">
<li>
{% if current_page.has_previous %}
<a href="?page={{ current_page_num|add:-1 }}" aria-label="Previous">
{% else %}
<a href="javascript:void(0)" aria-label="Previous">
{% endif %}
<span aria-hidden="true">上一页</span>
</a>
</li>
{% if current_page_num == 1 %}
<li class="active">
{% else %}
<li>
{% endif %}
<a href="?page=1">1</a></li>
{% if num_pages > 14 %}
<li><a href="javascript:void(0)">...</a></li>
{% endif %}
{% for num in page_range %}
{% if current_page_num == num %}
<li class="active">
{% else %}
<li>
{% endif %}
<a href="?page={{ num }}">{{ num }}</a></li>
{% endfor %}
{% if num_pages > 13 %}
<li><a href="javascript:void(0)">...</a></li>
{% endif %}
{% if current_page_num == num_pages %}
<li class="active">
{% else %}
<li>
{% endif %}
<a href="?page={{ num_pages }}">{{ num_pages }}</a></li>
<li>
{% if current_page.has_next %}
<a href="?page={{ current_page_num|add:1 }}" aria-label="Next">
{% else %}
<a href="javascript:void(0)" aria-label="Next">
{% endif %}
<span aria-hidden="true">下一页</span>
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
后台:
def index(request):
book_list = Book.objects.all()
paginator = Paginator(book_list,6)
count = paginator.count
num_pages = paginator.num_pages
page_range = paginator.page_range
try:
current_page_num = int(request.GET.get('page',1))
except:
current_page_num =1
current_page = paginator.page(current_page_num)
if num_pages > 13:
if current_page_num <7 :
page_range = range(2,12)
elif current_page_num +6 > num_pages:
page_range = range(num_pages-10,num_pages)
else:
page_range = range(current_page_num-5,current_page_num+6)
else:
page_range = range(2,13)
return render(request,'index.html',locals())
