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  • 分页器组件

    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
     # 你们 写:
        # for i in range(100):
        #     models.Book.objects.create(name='图书%s'%i,price=10+i)
        # 我写和以后你们写(批量插入)
        # 先造成100本书,放到列表中
        # ll=[]
        # for i in range(100):
        #     ll.append(models.Book(name='图书%s'%i,price=10+i))
        # # 批量插入,两个参数,第一个是对象列表,第二个是一次插入的数据量,不填,默认一次全插入
        # models.Book.objects.bulk_create(ll)
    
        # 查询所有图书
        book_list=models.Book.objects.all()
        # 分页器--类
        # 实例化产生一个对象
        # 两个参数:object_list:对象列表, per_page:每页显示的条数
        paginator=Paginator(book_list,10)
        # 对象内的属性
        # 数据总条数100条
        # print(paginator.count)
        # # 总页数  10页
        # print(paginator.num_pages)
        # # 页码数的列表
        # print(paginator.page_range)
        # # 取到第 x 页 ,返回一个Page对象
        # current_page=paginator.page(5)
        # # 当前页码内所有的数据
        # print(current_page.object_list)
        # # 是否有下一页
        # print(current_page.has_next())
        # # 是否有上一页
        # print(current_page.has_previous())
        # # 下一页页码数
        # print(current_page.next_page_number())
        # # 上一页的页码数
        # print(current_page.previous_page_number())
    部分parginator知识

    2 应用View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())

    3 模版层 index.html

    <!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/bootstrap@3.3.7/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_num|add:-1 }}" aria-label="Previous">#}
                            <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>

    4 核心逻辑

    '''
        显示左5,右5,总共11个页,
    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)
    其它情况,生成的列表就是pageinator的page_range
            page_range=paginator.page_range
    
        '''
    
    核心逻辑

    5 作业(利用ajax和装饰器结合传输数据)

    index.html

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <script src="/static/jquery-3.3.1.js"></script>
        <title>Title</title>
    </head>
    <body>
    <button id="btn">点我</button>
    </body>
    <script>
    
        $("#btn").click(function () {
            var dic = {'name': 'egon'}
            var da=JSON.stringify(dic)
            $.ajax({
                url: '/index/',
                type: 'post',
                contentType: 'application/json',
                data:da,
                success: function (data) {
                    console.log(data)
    
                }
    
            })
    
        })
    
    
    </script>
    </html>

    views 

    from django.shortcuts import render, HttpResponse
    
    # Create your views here.
    import json
    
    
    def auth_ajax(func):
        def inner(request, *args, **kwargs):
            request.data = request.POST
            print(request.data)
            try:
                request.data = json.loads(request.body.decode('utf-8'))
            except Exception as e:
                print(e)
            res = func(request, *args, **kwargs)
            return res
    
        return inner
    
    @auth_ajax
    def index(request):
        if request.method == 'GET':
            return render(request, 'index.html')
        elif request.method == 'POST':
            print(request.data)
            print(request.data.get('name'))
            return HttpResponse('ok')
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  • 原文地址:https://www.cnblogs.com/ouyang99-/p/9992947.html
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