16.分页
django 自带的分页:django paginator
参考:https://docs.djangoproject.com/en/1.10/topics/pagination/
>>> from django.core.paginator import Paginator
>>> objects = [‘john‘, ‘paul‘, ‘george‘, ‘ringo‘]
>>> p = Paginator(objects, 2)
>>> p.count
4
>>> p.num_pages ##一共多少页,也可说是最后一页的页数
2
>>> p.page_range
[1, 2]
>>>
>>> page1 = p.page(1)
>>> page1
<Page 1 of 2>
>>> page1.object_list
[‘john‘, ‘paul‘]
>>> page2 = p.page(2)
>>> page2.object_list
[‘george‘, ‘ringo‘]
>>> page2.has_next()
False
>>> page2.has_previous()
True
>>> page2.has_other_pages()
True
>>> page2.next_page_number()
Traceback (most recent call last):
...
EmptyPage: That page contains no results
>>> page2.previous_page_number()
1
>>> page2.start_index() # The 1-based index of the first item on this page
3
>>> page2.end_index() # The 1-based index of the last item on this page
4
>>> p.page(0)
Traceback (most recent call last):
...
EmptyPage: That page number is less than 1
>>> p.page(3)
Traceback (most recent call last):
...
EmptyPage: That page contains no results
###################################
###################################
################################### 后端处理
from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger
from django.shortcuts import render
def listing(request):
contact_list = Contacts.objects.all() ###把内容取出来,但不是真正取出去。
paginator = Paginator(contact_list, 25) # Show 25 contacts per page
page = request.GET.get(‘page‘) ##前台说要去那一页,就提交到这
try:
contacts = paginator.page(page)
except PageNotAnInteger:
# If page is not an integer, deliver first page. ##如果页面不是一个整数,交付第一页
contacts = paginator.page(1)
except EmptyPage:
# If page is out of range (e.g. 9999), deliver last page of results.
contacts = paginator.page(paginator.num_pages) ##如果取的页数超过最大页数,就返回最后一页
return render(request, ‘list.html‘, {‘contacts‘: contacts}) ##把获取到的页面返回到前台
###################################
###################################
################################### 前端处理
{% for contact in contacts %}
{# Each "contact" is a Contact model object. #}
{{ contact.full_name|upper }}<br />
...
{% endfor %}
<div class="pagination">
<span class="step-links">
{% if contacts.has_previous %} ##判断后端传来的页数,有没有上一页
<a href="?page={{ contacts.previous_page_number }}">previous</a>
{% endif %}
<span class="current">
Page {{ contacts.number }} of {{ contacts.paginator.num_pages }}.
</span>
{% if contacts.has_next %} ##判断后端传来的页数,有没有下一页
<a href="?page={{ contacts.next_page_number }}">next</a>
{% endif %} ### ?page ,加上‘?‘问号。 就是一个get方法。
</span>
</div>
###################################
###################################
################################### 前端处理,用bootstrap 实现, 作业:线上分页中的前后几页,而不是下面的全部页面都显示
<nav>
<ul class="pagination">
{% if articles.has_previous %}
<li>
<a href="?page={{ articles.previous_page_number }}" aria-label="Previous">
<span aria-hidden="true">
«
</span>
</a>
</li>
{% else %}
<li>
<a href="#" aria-label="Previous">
<span aria-hidden="true">
«
</span>
</a>
</li>
{% endif %}
{% for p_num in articles.paginator.page_range %}
{% if articles.number == p_num %}
<li class="active">
<a href="#">
{{ articles.number }}
<span class="sr-only">{{ articles.number }}
</span>
</a>
</li>
{% else %}
<li >
<a href="?page={{ p_num }}">
{{ p_num }}
</a>
</li>
{% endif %}
{% endfor %}
{% if articles.has_next %}
<li>
<a href="?page={{ articles.next_page_number }}" aria-label="Next">
<span aria-hidden="true">
»
</span>
</a>
</li>
{% else %}
<li>
<a href="#" aria-label="Next">
<span aria-hidden="true">
»
</span>
</a>
</li>
{% endif %}
</ul>
</nav>
下面这个实例，分页页面按钮数最多显示为3个！
实例:
后端:
def index(request): ##分页
articles_list = models.Article.objects.all().order_by(‘-publish_date‘) ###把内容取出来,但不是真正取出去。
paginator = Paginator(articles_list, 2) # Show 2 contacts per page
page = request.GET.get(‘page‘) ##前台说要去那一页,就提交到这
try:
articles = paginator.page(page)
except PageNotAnInteger:
# If page is not an integer, deliver first page. ##如果页面不是一个整数,交付第一页
articles = paginator.page(1)
except EmptyPage:
# If page is out of range (e.g. 9999), deliver last page of results.
articles = paginator.page(paginator.num_pages) ##如果取的页数超过最大页数,就返回最后一页
page_range = range(articles.number - 1 ,articles.number + 2)
max_page = paginator.num_pages
return render(request,‘index.html‘,{
‘articles‘: articles,
‘page_range‘: page_range,
‘max_page‘: max_page,
})
前端:
<div class="pagination">
<ul class="pagination">
{% if articles.has_previous %}
<li><a href="?page={{ articles.previous_page_number }}">previous</a>
</li>
{% endif %}
{% for p_num in page_range %}
{% if 0 < p_num and p_num < max_page %}
{% if articles.number == p_num %}
<li class="active">
<a href="#">
{{ articles.number }}
<span class="sr-only">{{ articles.number }}
</span>
</a>
</li>
{% else %}
<li >
<a href="?page={{ p_num }}">
{{ p_num }}
</a>
</li>
{% endif %}
{% endif %}
{% endfor %}
{% if articles.has_next %}
<li><a href="?page={{ articles.next_page_number }}">next</a></li>
{% endif %}
</ul>
</div>
时间： 2024-12-29 19:50:31