django 函数和类实现分页案例

方法一: 模拟分页
from django.shortcuts import render,HttpResponse
from app01 import models

def hostnames(request):
    current_page = int(request.GET.get('page'))  #获取当前页数
    per_page = 10                                #定义每页显示的页数
    all_data = models.Host.objects.all().count() #统计数据库数据条数
    all_page,b = divmod(all_data,per_page)       #获取分多少页显示 
    if b != 0:
        all_page += 1
    start_page = (current_page-1) * per_page   #定义从哪儿开始
    end_page = current_page * per_page         #定义从哪儿结束
    host_list = models.Host.objects.all()[start_page:end_page]  从数据获取展示的数据

    page_count = 11
    half_page_count = int(page_count /2)
    if all_page < page_count:
        page_start = 1
        page_end = page_count
    else:
        if current_page <= half_page_count:
            page_start = 1
            page_end = page_count
        else:
            if (current_page+5) > all_page:
                page_end = all_page
                page_start = all_page-page_count
            else:
                page_start = current_page -half_page_count
                page_end = current_page + half_page_count



    url_list = []
    if current_page <= 1:
        prev = '<a href="#">上一页</a>'
    else:
        prev = '<a href="/hostnames/?page=%s">上一页</a>'%(current_page-1)
    url_list.append(prev)
    for i in range(page_start,page_end+1):
        if current_page == i:
            tp = '<a class="active href="/hostnames/?page=%s">%s</a>' % (i, i)

        else:
            tp = '<a href="/hostnames/?page=%s">%s</a>' %(i,i)
        url_list.append(tp)

    if current_page >= all_page:
        next = '<a href="#">下一页</a>'
    else:
        next = '<a href="/hostnames/?page=%s">下一页</a>'%(current_page+1)
    url_list.append(next)
    page_str = "".join(url_list)
    print(page_str)
    return render(request,'hostnames.html',{'host_list':host_list,'page_str':page_str})

模拟分页结合bootstrape设置样式

后端代码
# 分页
users = [ {'username':'ivy_{}'.format(i),'pwd':'xxx'} for i in range(1,406)]
def user_list(request):
    try:
        page = int(request.GET.get('page',1))
        if page <= 0:
            page = 1
    except Exception:
        page = 1
    #每页显示的数据条数
    per_num = 10
    #总数据量
    all_count = len(users)

    #计算总页数
    all_page,more = divmod(all_count,per_num)
    if more:
        all_page+=1
    #最多显示的页码数
    max_show = 11
    half_show = max_show//2

    if all_page < max_show:
        page_start = 1
        page_end = all_page
    else:
        if page <= half_show:
            page_start =1
            page_end = max_show
        elif page + half_show > all_page:
            page_start = all_page - 11 +1
            page_end = all_page
        else:
            page_start = page - half_show
            page_end = page + half_show

    li_list = []
    #上一页
    if page ==1:
        li = '<li class="disabled"><a href="?page={}">上一页</a></li>'.format(page)
        li_list.append(li)
    else:
        li = '<li><a href="?page={}">上一页</a></li>'.format(page-1)
        li_list.append(li)
    for i in range(page_start,page_end+1):
        if i == page:
            li = '<li class="active"><a href="?page={}">{}</a></li>'.format(i,i)
        else:
            li = '<li><a href="?page={}">{}</a></li>'.format(i, i)
        li_list.append(li)
    # 下一页
    if page == all_page:
        li = '<li class="disabled"><a href="?page={}">下一页</a></li>'.format(page)
        li_list.append(li)
    else:
        li = '<li><a href="?page={}">下一页</a></li>'.format(page + 1)
        li_list.append(li)
    page_html = ''.join(li_list)

    start = (page-1)*per_num
    end = page * per_num
    return render(request,'user_list.html',{'users':users[start:end],'page_html':page_html})


模板文件代码:
{% extends 'layout.html' %}
{% block content %}
    <table class="table">
        <thead>
            <tr>
                <th>
                    用户名
                </th>
                <th>
                    密码
                </th>
            </tr>

        </thead>
        <tbody>
            {% for user in users %}
                <tr>
                    <td>{{ user.username }}</td>
                    <td>{{ user.pwd }}</td>
                </tr>
            {% endfor %}
            
        </tbody>
    </table>

    <nav aria-label="Page navigation">
  <ul class="pagination">
    {{ page_html | safe }}
      <form action="">
          <input type="number" name="page">
          <button>跳转</button>

      </form>
    

  </ul>
</nav>
{% endblock %}

 

类封装和使用

封装代码

from django.utils.safestring import mark_safe
class Pagination():
    def __init__(self,page,all_count,per_num=10,max_show=11):
        try:
            self.page = int(page)
            if self.page <= 0:
                self.page = 1
        except Exception:
            self.page = 1
        # 每页显示的数据条数
        per_num = per_num
        # 总数据量
        all_count = all_count

        # 计算总页数
        self.all_page, more = divmod(all_count, per_num)
        if more:
            self.all_page += 1
        # 最多显示的页码数
        max_show = max_show
        half_show = max_show // 2

        if self.all_page < max_show:
            page_start = 1
            page_end = self.all_page
        else:
            if self.page <= half_show:
                page_start = 1
                page_end = max_show
            elif self.page + half_show > self.all_page:
                page_start = self.all_page - 11 + 1
                page_end = self.all_page
            else:
                page_start =self.page - half_show
                page_end = self.page + half_show

        self.page_start = page_start
        self.page_end = page_end
        # 切片起始位置
        self.start = (self.page - 1) * per_num
        # 切片结束位置
        self.end = self.page * per_num

    @property
    def page_html(self):
        li_list = []
        # 上一页
        if self.page == 1:
            li = '<li class="disabled"><a href="?page={}">上一页</a></li>'.format(self.page)
            li_list.append(li)
        else:
            li = '<li><a href="?page={}">上一页</a></li>'.format(self.page - 1)
            li_list.append(li)
        for i in range(self.page_start, self.page_end + 1):
            if i == self.page:
                li = '<li class="active"><a href="?page={}">{}</a></li>'.format(i, i)
            else:
                li = '<li><a href="?page={}">{}</a></li>'.format(i, i)
            li_list.append(li)
        # 下一页
        if self.page == self.all_page:
            li = '<li class="disabled"><a href="?page={}">下一页</a></li>'.format(self.page)
            li_list.append(li)
        else:
            li = '<li><a href="?page={}">下一页</a></li>'.format(self.page + 1)
            li_list.append(li)

        s = ' <nav aria-label="Page navigation"><ul class="pagination">{}</ul></nav>'.format(''.join(li_list))
        return mark_safe(s)


调用代码
# 分页
users = [ {'username':'ivy_{}'.format(i),'pwd':'xxx'} for i in range(1,406)]
from utils import pagination
def user_list(request):
    page_obj = pagination.Pagination(request.GET.get('page'),len(users))

    return render(request,'user_list.html',
                  {'users':users[page_obj.start:page_obj.end],'page_html':page_obj.page_html})

模板文件代码
{% extends 'layout.html' %}
{% block content %}
    <table class="table">
        <thead>
            <tr>
                <th>
                    用户名
                </th>
                <th>
                    密码
                </th>
            </tr>

        </thead>
        <tbody>
            {% for user in users %}
                <tr>
                    <td>{{ user.username }}</td>
                    <td>{{ user.pwd }}</td>
                </tr>
            {% endfor %}
            
        </tbody>
    </table>

    {{ page_html }}
{% endblock %}

{#跳转代码#}
{# <form action="">#}
{#          <input type="number" name="page">#}
{#          <button>跳转</button>#}
{##}
{#      </form>#}