自定义分页 - 润新知

1. 浏览器手动访问: http://127.0.0.1:8000/host/?page=2

    后端
        Host_list = []
        for i in range(1,100):
            Host_list.append("host%s"%i)


        def host(request):

            current_page = int(request.GET.get("page"))

            per_page_count = 10

            start = (current_page -1) * per_page_count
            end = current_page * per_page_count
            host_list = Host_list[start:end]


            return render(request,"host_list.html",{"host_list":host_list})

    前端
        <ul>
            {% for item in host_list %}
                <li>{{ item }}</li>
            {% endfor %}
        </ul>

View Code

2. 显示页码

def host(request):
    try:
        current_page = int(request.GET.get("page"))
    except Exception:
        current_page =1

    per_page_count = 10

    start = (current_page -1) * per_page_count
    end = current_page * per_page_count
    host_list = Host_list[start:end]


    #数据总条数
    total_count = len(Host_list)
    #页面显示的最大页码
    max_page_num,div = divmod(total_count,per_page_count)
    if div:
        max_page_num += 1

    page_html_list = []
    for i in range(1,max_page_num +1):
        if i == current_page:
            temp = '<a class="active" href="/host/?page=%s">%s</a>'%(i,i)
        else:
            temp = '<a href="/host/?page=%s">%s</a>' % (i, i)
        page_html_list.append(temp)
    page_html = "".join(page_html_list)

    return render(request,"host_list.html",{"host_list":host_list,"page_html":page_html})

Views.py

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .pager a{
            display: inline-block;
            padding: 2px 8px;
            margin: 0 5px;
            border: 1px solid cadetblue;
        }
        .pager a.active{
            background-color: green;
            color: white;
        }
    </style>
</head>
<body>
    <ul>
        {% for item in host_list %}
            <li>{{ item }}</li>
        {% endfor %}
    </ul>
    <div class="pager">
        {{ page_html|safe }}
    </div>
</body>
</html>

host_list.html

3. 显示指定数量的页码

Host_list = []
for i in range(1,1000):
    Host_list.append("host%s"%i)





def host(request):
    try:
        current_page = int(request.GET.get("page"))
    except Exception:
        current_page =1

    per_page_count = 10

    start = (current_page -1) * per_page_count
    end = current_page * per_page_count
    host_list = Host_list[start:end]


    #数据总条数
    total_count = len(Host_list)
    #页面显示的最大页码
    max_page_num,div = divmod(total_count,per_page_count)
    if div:
        max_page_num += 1


    #页面上默认显示11个页面
    max_page_count = 11
    half_max_page_count = int((max_page_count-1)/2)

    page_start = current_page - half_max_page_count
    page_end = current_page + half_max_page_count



    page_html_list = []
    for i in range(page_start,page_end+1):
        if i == current_page:
            temp = '<a class="active" href="/host/?page=%s">%s</a>'%(i,i)
        else:
            temp = '<a href="/host/?page=%s">%s</a>' % (i, i)
        page_html_list.append(temp)
    page_html = "".join(page_html_list)

    return render(request,"host_list.html",{"host_list":host_list,"page_html":page_html})

Views.py

4. 解决极限的选择开始页和结尾页

Host_list = []
for i in range(1,1000):
    Host_list.append("host%s"%i)





def host(request):
    try:
        current_page = int(request.GET.get("page"))
    except Exception:
        current_page =1

    per_page_count = 10

    start = (current_page -1) * per_page_count
    end = current_page * per_page_count
    host_list = Host_list[start:end]


    #数据总条数
    total_count = len(Host_list)
    #页面显示的最大页码
    max_page_num,div = divmod(total_count,per_page_count)
    if div:
        max_page_num += 1


    #页面上默认显示11个页面
    page_count = 11
    half_max_page_count = int((page_count-1)/2)


    #如果总页数小于显示的页数
    if max_page_num < page_count:
        page_start = 1
        page_end = max_page_num
    else:
        #最左边判断
        if current_page <= half_max_page_count:
            page_start =1
            page_end = page_count
        else:
            #最右边判断
            if (current_page + half_max_page_count) >max_page_num:
                page_start = max_page_num - page_count + 1
                page_end = max_page_num
            else:
                page_start = current_page - half_max_page_count
                page_end = current_page + half_max_page_count



    page_html_list = []
    for i in range(page_start,page_end+1):
        if i == current_page:
            temp = '<a class="active" href="/host/?page=%s">%s</a>'%(i,i)
        else:
            temp = '<a href="/host/?page=%s">%s</a>' % (i, i)
        page_html_list.append(temp)
    page_html = "".join(page_html_list)

    return render(request,"host_list.html",{"host_list":host_list,"page_html":page_html})

Views.py

5. 组件分装为类

"""
自定义分页组件的使用方法：
    pager_obj = Pagination(request.GET.get('page',1),len(HOST_LIST),request.path_info)
    host_list = HOST_LIST[pager_obj.start:pager_obj.end]
    html = pager_obj.page_html()
    return render(request,'hosts.html',{'host_list':host_list,"page_html":html})
"""

class Pagination(object):
    """
    自定义分页
    """
    def __init__(self,current_page,total_count,base_url,per_page_count=10,pager_count=11):
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        if current_page <=0:
            current_page = 1
        self.current_page = current_page
        # 数据总条数
        self.total_count = total_count

        # 每页显示10条数据
        self.per_page_count = per_page_count

        # 页面上应该显示的最大页码
        max_page_num, div = divmod(total_count, per_page_count)
        if div:
            max_page_num += 1
        self.max_page_num = max_page_num

        # 页面上默认显示11个页面（当前页在中间）
        self.pager_count = pager_count
        self.half_pager_count = int((pager_count - 1) / 2)

        # URL前缀
        self.base_url = base_url
    @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

    def page_html(self):
        # 如果总页数 <= 11
        if self.max_page_num <= self.pager_count:
            pager_start = 1
            pager_end = self.max_page_num
        # 如果总页数 > 11
        else:
            # 如果当前页 <= 5
            if self.current_page <= self.pager_count:
                pager_start = 1
                pager_end = self.pager_count
            else:
                # 当前页 + 5 > 总页码
                if (self.current_page + self.pager_count) > self.max_page_num:
                    pager_end = self.max_page_num
                    pager_start = self.max_page_num - self.pager_count + 1
                else:
                    pager_start = self.current_page - self.pager_count
                    pager_end = self.current_page + self.pager_count

        page_html_list = []
        first_page = '<a href="/host/?page=1">首页</a>'
        page_html_list.append(first_page)
        for i in range(pager_start, pager_end + 1):
            if i == self.current_page:
                temp = '<a class="active" href="%s?page=%s">%s</a>' % (self.base_url,i, i,)
            else:
                temp = '<a href="%s?page=%s">%s</a>' % (self.base_url,i, i,)
            page_html_list.append(temp)
        end_page = '<a href="/host/?page=%s">尾页</a>' % self.max_page_num
        page_html_list.append(end_page)

        return ''.join(page_html_list)

View Code

6. 保留原搜索条件

保留原搜索条件
    1. 方式一:
        - 缺点: 列表页面跳到编辑页面除了加列表页面的参数外 还增加了编辑页面的参数 再次返回列表页面获取到的参数无法确认哪些时列表页面的参数

        - 列表页面
            - 获取当前url的参数request.GET.urlencode()
            - 增加到 编辑按钮URL的后面
            - 增加到 增加按钮URL的后面
        - 编辑 增加 页面提交
            - POST提交时 获取原来列表页面传过来的条件request.GET.urlencode()
            - 拼接URL /host/？原来的条件
        
        list页面：

            list_condition = request.GET.urlencode()

            {% for item in host_list %}
                <li>{{ item }} <a href="/edit/54/?{{ list_condition }}">编辑</a></li>
            {% endfor %}
    
        add/edit页面：http://127.0.0.1:8000/edit/10/?page=5&id__gt=4

            def edit_host(request,pk):
                if request.method == "GET":
                    return render(request,'edit_host.html')
                else:
                    # 修改成功 /hosts/?page=5&id__gt=4
                    url = "/hosts/?%s" %(request.GET.urlencode())
                    return redirect(url)

    2. 方式二:
        - 把列表页面的参数打包 赋值一个key _list_file = "page=15"
        - 列表页面
            - form django.http import QueryDict
            params = QueryDict(mutable=True)
            params['_list_filter'] = request.GET.urlencode()
            list_codition = params.urlencode()
            把list_codition传给编辑的值
        - 编辑页面
            url = request.GET.get("_list_filter")
            return redict(url)

        list页面： http://127.0.0.1:8000/hosts/?page=5&id__gt=4
            
            params = QueryDict(mutable=True)
            params['_list_filter'] = request.GET.urlencode()
            list_condition = params.urlencode()
            
            
            {% for item in host_list %}
                <li>{{ item }} <a href="/edit/54/?{{ list_condition }}">编辑</a></li>
            {% endfor %}
    
        add/edit页面:http://127.0.0.1:8000/edit/54/?_list_filter=page%3D5%26id__gt%3D4
                
            def edit_host(request,pk):
            if request.method == "GET":
                return render(request,'edit_host.html')
            else:
                # 修改成功 /hosts/?page=5&id__gt=4
                url = "/hosts/?%s" %(request.GET.get('_list_filter'))
                return redirect(url)

7. 之后调分页

current_page = request.GET.get('page', 1)
total_count = self.model_class.objects.all().count()
base_url = request.path_info
 
page_list = Pagination(current_page, total_count, base_url, request.GET, per_page_count=2, pager_count=5)
html = page_list.page_html()
data_list = self.model_class.objects.all()[page_list.start:page_list.end]
 
return render(request, 'stark/changelist.html',
              {'data_list': data_list, 'head_list': head_list, " "page_html": html})

<nav aria-label="Page navigation" class="pull-right" >
    <ul class="pagination">
    {{ page_html|safe }}
    </ul>
</nav>

"""
自定义分页组件的使用方法：
    pager_obj = Pagination(request.GET.get('page',1),len(HOST_LIST),request.path_info,request.GET)
    host_list = HOST_LIST[pager_obj.start:pager_obj.end]
    html = pager_obj.page_html()
    return render(request,'hosts.html',{'host_list':host_list,"page_html":html})
"""

class Pagination(object):
    """
    自定义分页
    """
    def __init__(self,current_page,total_count,base_url,pamams,per_page_count=10,pager_count=11):
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        if current_page <=0:
            current_page = 1
        self.current_page = current_page
        # 数据总条数
        self.total_count = total_count

        # 每页显示10条数据
        self.per_page_count = per_page_count

        # 页面上应该显示的最大页码
        max_page_num, div = divmod(total_count, per_page_count)
        if div:
            max_page_num += 1
        self.max_page_num = max_page_num

        # 页面上默认显示11个页面（当前页在中间）
        self.pager_count = pager_count
        self.half_pager_count = int((pager_count - 1) / 2)

        # URL前缀
        self.base_url = base_url


        import copy
        pamams = copy.deepcopy(pamams)
        pamams._mutable = True
        self.pamams = pamams

    @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

    def page_html(self):
        # 如果总页数 <= 11
        if self.max_page_num <= self.pager_count:
            pager_start = 1
            pager_end = self.max_page_num
        # 如果总页数 > 11
        else:
            # 如果当前页 <= 5
            if self.current_page <= self.pager_count:
                pager_start = 1
                pager_end = self.pager_count
            else:
                # 当前页 + 5 > 总页码
                if (self.current_page + self.pager_count) > self.max_page_num:
                    pager_end = self.max_page_num
                    pager_start = self.max_page_num - self.pager_count + 1
                else:
                    pager_start = self.current_page - self.pager_count
                    pager_end = self.current_page + self.pager_count

        page_html_list = []
        self.pamams['page'] = 1
        first_page = '<li><a href="%s?%s">首页</a></li>'%(self.base_url,self.pamams.urlencode())
        page_html_list.append(first_page)
        for i in range(pager_start, pager_end + 1):
            self.pamams['page'] = i
            if i == self.current_page:
                temp = '<li class="active"><a href="%s?%s">%s</a></li>' % (self.base_url,self.pamams.urlencode(), i,)
            else:
                temp = '<li><a href="%s?%s">%s</a></li>' % (self.base_url,self.pamams.urlencode(), i,)
            page_html_list.append(temp)

        #尾页
        self.pamams['page'] = self.max_page_num
        end_page = '<li><a href="%s?%s">尾页</a></li>' % (self.base_url,self.pamams.urlencode(),)
        page_html_list.append(end_page)

        return ''.join(page_html_list)

page.py