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django_分页

django_分页

作者: 两点半的杂货铺 | 来源:发表于2018-01-21 23:11 被阅读0次

    一、基础篇

    image.png

    =
    view模块处理

    li = []
    for i in range(101):
        li.append(i)
    def user_list(request):
        #当page 关键字不存在时 默认1
        current_page = request.GET.get('page',1)
        current_page = int(current_page)
        #页数减-1*10,切片的起始位置
        start = (current_page-1)*10
        # 页数减*10,切片的结束位置
        end = (current_page)*10
        data = li[start:end]
        #显示页数,因为页面没有循环数字的方法,所以后台处理
        page_num,mod_num = divmod(len(li),10)
        #余数不为0页数加一
        if mod_num:
            page_num += 1
        temp_list = []
        for i in range(1,page_num+1):
            if i==current_page:
                temp = '<a class="page active" href="/tp5/?page=%s">%s</a>'%(i,i)
            else:
                temp = '<a class="page" href="/tp5/?page=%s">%s</a>'%(i,i)
            temp_list.append(temp)
        temp_num = ''.join(temp_list)
        return render(request,'user_list.html',{'num':temp_num,'data':data})
    

    html 页面

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <style>
            .pageination .page{
                display: inline-block;
                padding: 5px;
                background-color: chocolate;
                margin: 5px;
            }
            .pageination .page.active{
                background-color: greenyellow;
            }
        </style>
    </head>
    <body>
    <ul>
        {% for i in data %}
            <li>  {{ i }}</li>
        {% endfor %}
    </ul>
    <br>
        <div class="pageination">
            {{ num|safe }}
        </div>
    </body>
    </html>
    

    二、讲解

    对页数限制的讲解

    page_count   显示条数
    current_page 当前页数
    page_num     总页数
    11           页码
    
    总页数小于实际展示页数
    总页数大于实际展示页数
    
    前提条件总页数11时 
    
        当前页<=6
            开始页1
            结束页11
        当前页>6
            开始页=当前页-5
            结束页=当前页+6
            当前页+5>总页数
                结束页=总页数+1
                开始页=总页数-10
    

    转换成代码

    if page_num<11:
        start_index = 1
        end_index = page_num
    else:
        if current_page<=6:  
            start_index = 1
            end_index = 11
        else:
            start_index = current_page -5
            end_index = current_page +6
            if current_page+5>page_num:
                end_index = page_num+1
                start_index = page_num-10
    
    

    上一页/下一页操作

    上一页
    当前页等于1时
        上一页功能失效
    当前页大于1时
        当前页-1
    
    下一页
    当前页等于总页数时
        下一页功能失效
    当前页小于总页数时
        当前页+1
    

    代码如下

    if current_page ==1:
        prev = '<a class='page' href="javascript:viod(0)">上一页</a>'
    else:
        prev = '<a class='page'  href="/tp5/?page=%s">上一页</a>'%(current_page-1)
    
    
    if current_page ==page_num:
        prev = '<a class='page' href="javascript:viod(0)">下一页</a>'
    else:
        prev = '<a class='page'  href="/tp5/?page=%s">下一页</a>'%(current_page+1)
    

    跳转代码如下:

     jump ='''
        <input type='text' /><a onclick='jumpTo(this, "/tp5/?page=");' id='ii'>GO</a>
        <script>
            function jumpTo(ths,base){
                var val = ths.previousSibling.value;
                location.href = base + val;
            }
        </script>
        '''
    

    分页整体代码如下:

    def user_list(request):
        page_count = 10
        #当page 关键字不存在时 默认1
        current_page = request.GET.get('page',1)
        current_page = int(current_page)
        #页数减-1*10,切片的起始位置
        start = (current_page-1)*page_count
        # 页数减*10,切片的结束位置
        end = (current_page)*page_count
        data = li[start:end]
        #显示页数,因为页面没有循环数字的方法,所以后台处理
        page_num,mod_num = divmod(len(li),page_count)
        #余数不为0页数加一
        if mod_num:
            page_num += 1
        temp_list = []
    
        #显示最大页数
        max_page = 11
        if page_num<max_page:
            start_index =1
            end_indx =max_page
        else:
            if current_page<=(max_page+1)/2:
                start_index = 1
                end_indx = max_page
            else:
                start_index = current_page-(max_page-1)/2
                end_indx = current_page+(max_page+1)/2
                if current_page+(max_page-1)/2>page_num:
                    start_index = page_num-max_page+1
                    end_indx = page_num+1
    
        if current_page == 1:
            prev = '<a class="page" href="javascript:viod(0)">上一页</a>'
        else:
            prev = '<a class="page"  href="/tp5/?page=%s">上一页</a>' % (current_page - 1)
        temp_list.append(prev)
        # 起始页
        for i in range(int(start_index),int(end_indx)):
            if i==current_page:
                temp = '<a class="page active" href="/tp5/?page=%s">%s</a>'%(i,i)
            else:
                temp = '<a class="page" href="/tp5/?page=%s">%s</a>'%(i,i)
            temp_list.append(temp)
        if current_page == page_num:
            prev = '<a class="page" href="javascript:viod(0)">上一页</a>'
        else:
            prev = '<a class="page"  href="/tp5/?page=%s">上一页</a>' % (current_page + 1)
        temp_list.append(prev)
        jump ='''
        <input type='text' /><a onclick='jumpTo(this, "/tp5/?page=");' id='ii'>GO</a>
        <script>
            function jumpTo(ths,base){
                var val = ths.previousSibling.value;
                location.href = base + val;
            }
        </script>
        '''
        temp_list.append(jump)
        temp_num = ''.join(temp_list)
        return render(request,'user_list.html',{'num':temp_num,'data':data})
    
    

    三、打包成类

    class page():
        '''
        start:获取每页的第一条数据
        end:获取每页的最后一条数据
        all_count: 获取总页数
        page_str: 分页展示,上一页,下一页,跳转
        '''
        def __init__(self,current_page,date_count,page_count=10,max_page = 11):
            '''
            :param current_page: 当前页数,通过request.GET获取
            :param date_count:   数据总个数,用divmod进行取余判断总页数
            :param page_count:   每页显示数据的个数
            :param max_page:     网页可显示的最大总页数
            '''
            self.current_page = current_page
            self.data_count = date_count
            self.page_count = page_count
            self.max_page = max_page
    
        @property
        def start(self):
            '''
            :return: (当前页-1)*每页展示条数==每页展示数据的第一条
            '''
            return (self.current_page-1)*self.page_count
        @property
        def end(self):
            '''
            :return:  当前页*每页展示条数==每页展示数据的最后一条
            '''
            return self.current_page*self.page_count
    
        @property
        def all_count(self):
            '''
            :param page_all:   取余的方法,得到商
            :param mod_num:    取余的方法,得到余
            :return:           返回实际总页数
            '''
            v =self.data_count
            page_all, mod_num = divmod(v, self.page_count)
            if mod_num:
                page_all += 1
            return page_all
    
        def page_str(self):
            temp_list = []
            if self.all_count < self.max_page:
                start_index = 1
                end_indx = self.max_page
            else:
                if self.current_page <= (self.max_page + 1) / 2:
                    start_index = 1
                    end_indx =self.max_page
                else:
                    start_index = self.current_page - (self.max_page - 1) / 2
                    end_indx = self.current_page + (self.max_page + 1) / 2
                    if self.current_page + (self.max_page - 1) / 2 > self.all_count:
                        start_index = self.all_count - self.max_page + 1
                        end_indx = self.all_count + 1
    
            if self.current_page == 1:
                prev = '<a class="page" href="javascript:viod(0)">上一页</a>'
            else:
                prev = '<a class="page"  href="/tp5/?page=%s">上一页</a>' % (self.current_page - 1)
            temp_list.append(prev)
            # 起始页
            for i in range(int(start_index), int(end_indx)):
                if i == self.current_page:
                    temp = '<a class="page active" href="/tp5/?page=%s">%s</a>' % (i, i)
                else:
                    temp = '<a class="page" href="/tp5/?page=%s">%s</a>' % (i, i)
                temp_list.append(temp)
            if self.current_page ==self.all_count:
                prev = '<a class="page" href="javascript:viod(0)">上一页</a>'
            else:
                prev = '<a class="page"  href="/tp5/?page=%s">上一页</a>' % (self.current_page + 1)
            temp_list.append(prev)
            jump = '''
               <input type='text' /><a onclick='jumpTo(this, "/tp5/?page=");' id='ii'>GO</a>
               <script>
                   function jumpTo(ths,base){
                       var val = ths.previousSibling.value;
                       location.href = base + val;
                   }
               </script>
               '''
            temp_list.append(jump)
            temp_num = ''.join(temp_list)
            return temp_num
    
    

    使用类

    def user_list(request):
        page_count = 10
        #当page 关键字不存在时 默认1
        current_page = request.GET.get('page',1)
        current_page = int(current_page)
        #创建分页对象
        page_obj = page(current_page,len(li))
        #每页数据的起始数据,结束数据
        data = li[page_obj.start:page_obj.end]
        temp_num=page_obj.page_str()
        return render(request,'user_list.html',{'num':temp_num,'data':data})
    
    
    • 直接使用版本

    __author__ = 'Administrator'
    from django.utils.safestring import mark_safe
    
    
    class Pagination(object):
        def __init__(self, current_page, data_count, per_page_count=1, pager_num=7):
            try:
                self.current_page = int(current_page)
            except Exception as e:
                self.current_page = 1
            self.data_count = data_count
            self.per_page_count = per_page_count
            self.pager_num = pager_num
    
        @property
        def start(self):
            return (self.current_page - 1) * self.per_page_count
    
        @property
        def end(self):
            return self.current_page * self.per_page_count
    
        @property
        def total_count(self):
            v, y = divmod(self.data_count, self.per_page_count)
            if y:
                v += 1
            return v
    
        def page_str(self, base_url):
            page_list = []
    
            if self.total_count < self.pager_num:
                start_index = 1
                end_index = self.total_count + 1
            else:
                if self.current_page <= (self.pager_num + 1) / 2:
                    start_index = 1
                    end_index = self.pager_num + 1
                else:
                    start_index = self.current_page - (self.pager_num - 1) / 2
                    end_index = self.current_page + (self.pager_num + 1) / 2
                    if (self.current_page + (self.pager_num - 1) / 2) > self.total_count:
                        end_index = self.total_count + 1
                        start_index = self.total_count - self.pager_num + 1
    
            if self.current_page == 1:
                prev = '<li><a class="page" href="javascript:void(0);">上一页</a></li>'
            else:
                prev = '<li><a class="page" href="%s?p=%s">上一页</a></li>' % (base_url, self.current_page - 1,)
            page_list.append(prev)
    
            for i in range(int(start_index), int(end_index)):
                if i == self.current_page:
                    temp = '<li class="active"><a class="page active" href="%s?p=%s">%s</a></li>' % (base_url, i, i)
                else:
                    temp = '<li><a class="page" href="%s?p=%s">%s</a></li>' % (base_url, i, i)
                page_list.append(temp)
    
            if self.current_page == self.total_count:
                nex = '<li><a class="page" href="javascript:void(0);">下一页</a></li>'
            else:
                nex = '<li><a class="page" href="%s?p=%s">下一页</a></li>' % (base_url, self.current_page + 1,)
            page_list.append(nex)
    
            # jump = """
            # <input type='text'  /><a onclick='jumpTo(this, "%s?p=");'>GO</a>
            # <script>
            #     function jumpTo(ths,base){
            #         var val = ths.previousSibling.value;
            #         location.href = base + val;
            #     }
            # </script>
            # """ % (base_url,)
            #
            # page_list.append(jump)
    
            page_str = mark_safe("".join(page_list))
    
            return page_str
    
    

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