一、分页器
数据量大的话，可以分页获取，查看
例如：图书管理中，如果有成千上万本书，要是都在一个页面中渲染出来，会影响页面美观，所以就要用分页器分页渲染
二、分页器的使用
基本写法
基本写法:
后端:
总数据拿出来
生成分页器Paginator对象(对象里有属性和方法)
生成当前页的对象,current_page=paginator.page(当前页码)
取出前台传过来的页码,current_page_num = int(request.GET.get(‘page‘))
-需要有异常捕获
-捕获到,把当前页码设置成第一页
前端:
-for循环总页列表
-点某一页,跳到指定页码,<li><a href="/index/?page={{ foo }}">{{ foo }}</a></li>
-上一页,下一页的处理:需要有判断,判断是否有上一页,下一页
# 判断总页码数是否大于11,不大于11,走else:把总页码数,赋给page_range(前端循环页码列表,循环的就是page_range)
if paginator.num_pages >11:
# 当前页码数-5大于1的时候,page_range应该是,page_range就是1到11页?
if current_page_num-5<1:
page_range=range(1,12)
elif current_page_num+5>paginator.num_pages:
# 当前页码数+5大于总页码数,总页码-10,到总页码+1之间
page_range=range(paginator.num_pages-10,paginator.num_pages+1)
else:
#其他情况,左5,右6推算,也就是:range(current_page_num - 5, current_page_num + 6)
page_range = range(current_page_num - 5, current_page_num + 6)
else:
#小于11,有多少页,就显示多少页
page_range=paginator.page_range
from django.core.paginator import Paginator # 对象参数 1. Paginator对象： paginator = Paginator(user_list, 10) # per_page: 每页显示条目数量 # count: 数据总个数 count = paginator.count # num_pages:总页数，它是一个对象的方法，通过装饰器伪装成对象属性 page_num = paginator.num_pages # page_range:总页数的索引范围，如: (1,10),(1,200) PageRange = paginator.page_range # page: page对象，传一个数字，假如你想取到第1页，就传1进去，会返回一个page对象，这个对象里是当前页的一些对象 page_obj = paginator.page(1) 2. page对象：page=paginator.page(1) # has_next 是否有下一页,它的返回值是一个布尔类型 page.has_next() # next_page_number 下一页页码,它的返回值是一个int类型 page.next_page_number() # has_previous 是否有上一页,它的返回值是一个布尔类型 page.has_previous() # previous_page_number 上一页页码,它的返回值是一个int类型 page.has_previous() # object_list 分页之后的数据列表 page.object_list() # number 当前页 page.number() # paginator paginator对象
三、案例
1、模板层
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<title>Title</title>
</head>
<body>
<div class="row">
<div class="col-md-6 col-md-offset-3">
<table class="table table-striped">
<thead>
<tr>
<th>书名</th>
<th>价格</th>
</tr>
</thead>
<tbody>
{% for book in current_page %}
<tr>
<td>{{ book.name }}</td>
<td>{{ book.price }}</td>
</tr>
{% endfor %}
</tbody>
</table>
<nav aria-label="Page navigation">
<ul class="pagination">
{% if current_page.has_previous %}
<li>
<a href="/index/?page={{ current_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_num == foo %}
{# 当前页码等于循环到的页码数,变色#}
<li class="active"><a href="/index/?page={{ foo }}">{{ foo }}</a></li>
{% else %}
<li><a href="?page={{ foo }}">{{ foo }}</a></li>
{% endif %}
{% endfor %}
{% if current_page.has_next %}
<li>
{# <a href="/index/?page={{ current_page_num|add:1 }}" aria-label="Next">#}
<a href="/index/?page={{ current_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>
</div>
</div>
</body>
</html>
2、视图层
def index(request):
book_list = models.Book.objects.all()
paginator = Paginator(book_list, 3)
# 如果页码数多,让它显示前5,后5,中间是当前在的页码
try:
current_page_num = int(request.GET.get(‘page‘))
current_page = paginator.page(current_page_num)
print(current_page.object_list)
# 总页码数,大于11的时候
if paginator.num_pages >11:
# 当前页码数-5大于1的时候,page_range应该是?
if current_page_num-5<1:
page_range=range(1,12)
elif current_page_num+5>paginator.num_pages:
# 当前页码数+5大于总页码数,总页码数往前推11个
page_range=range(paginator.num_pages-10,paginator.num_pages+1)
else:
page_range = range(current_page_num - 5, current_page_num + 6)
else:
#小于11,有多少页,就显示多少页
page_range=paginator.page_range
except Exception as e:
current_page_num = 1
current_page = paginator.page(current_page_num)
return render(request, ‘index_next.html‘, locals())
<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><!-- 最新版本的 Bootstrap 核心 CSS 文件 --><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous"><title>Title</title></head><body><div class="row"><div class="col-md-6 col-md-offset-3"><table class="table table-striped"><thead><tr><th>书名</th><th>价格</th></tr></thead><tbody>
{% for book in current_page %}
<tr><td>{{ book.name }}</td><td>{{ book.price }}</td></tr>
{% endfor %}
</tbody></table><nav aria-label="Page navigation"><ul class="pagination">
{% if current_page.has_previous %}
<li><a href="/index/?page={{ current_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_num == foo %}
{# 当前页码等于循环到的页码数,变色#}
<li class="active"><a href="/index/?page={{ foo }}">{{ foo }}</a></li>
{% else %}
<li><a href="?page={{ foo }}">{{ foo }}</a></li>
{% endif %}
{% endfor %}
{% if current_page.has_next %}
<li>
{# <a href="/index/?page={{ current_page_num|add:1 }}" aria-label="Next">#}
<a href="/index/?page={{ current_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></div></div></body></html>
原文地址：https://www.cnblogs.com/zhangbingsheng/p/10663929.html