一. Django的分頁器
1. view（視圖層）
from django.shortcuts import render, redirect from django.views import View from app01 import models from django.core.paginator import Paginator import random class Index(View): def get(self, request): """ 批量增加測試數據 book_list = [] for i in range(1, 101): # models.Book.objects.create(title="book_%s" % i, price=random.randint(20, 300)) # 執行效率低 book_list.append(models.Book(title="book_%s" % i, price=random.randint(20, 300))) models.Book.objects.bulk_create(book_list) # 批量新增數據 """ """ # 分頁器的基本語法 book_list = models.Book.objects.all() # 實例化分頁器對象 paginator = Paginator(book_list, 10) print("count", paginator.count) # 數據的總數 print("num_pages", paginator.num_pages) # 分頁的總頁數 print("page_range", paginator.page_range) # 頁數的范圍列表 page1 = paginator.get_page(1) # 獲取第一頁的所有數據 for i in page1: # 遍歷第一頁所有數據對象 print(i) print(page1.object_list) # 第一頁的所用數據 page2 = paginator.get_page(2) # 獲取第二頁的所有數據 print(page2.has_next()) # 是否有下一頁 print(page2.next_page_number()) # 下一頁的頁碼 print(page2.has_previous()) # 是否有上一頁 print(page2.previous_page_number()) # 上一頁的頁碼 # 拋錯 # page=paginator.page(22) # error:EmptyPage # page=paginator.page("z") # error:PageNotAnInteger """ # ############# django分頁器的基本使用 ################## book_list = models.Book.objects.all() paginator = Paginator(book_list, 10) current_page = int(request.GET.get("page") if request.GET.get("page") and request.GET.get("page").isdigit() else 1) # 獲取頁碼 page = paginator.get_page(current_page) # 獲取當前頁碼的所有數據 return render(request, "index.html", {"paginator": paginator, "page": page, "current_page": current_page})
2. template（模板層）
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title></title> <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"> </head> <body> <h3>書籍列表</h3> <ul> {% for book in page %} <li>{{ book.title }} --- {{ book.price }}</li> {% endfor %} </ul> <nav aria-label="Page navigation"> <ul class="pagination"> <li><a href="?page=1">首頁</a></li> {% if page.has_previous %} <li><a href="?page={{ page.previous_page_number }}">上一頁</a></li> {% else %} <li class="disabled"><a href="javascript:void(0);">上一頁</a></li> {% endif %} {% for num in paginator.page_range %} {% if current_page == num %} <li class="active"><a href="?page={{ num }}">{{ num }}</a></li> {% else %} <li><a href="?page={{ num }}">{{ num }}</a></li> {% endif %} {% endfor %} {% if page.has_next %} <li><a href="?page={{ page.next_page_number }}">下一頁</a></li> {% else %} <li class="disabled"><a href="javascript:void(0);">下一頁</a></li> {% endif %} <li><a href="?page={{ paginator.num_pages }}">尾頁</a></li> </ul> </nav> </body> </html>
二. Django分頁器擴展
上面的示例，看似已經完成了分頁的效果，但是，如果我們把每頁顯示的數量改小一點看一下效果。
這顯然是有問題的，那么，下面我們就來優化一下。
1. view（視圖層）
# ############# django分頁器的基本使用 ################## book_list = models.Book.objects.all() paginator = Paginator(book_list, 2) current_page = int(request.GET.get("page") if request.GET.get("page") and request.GET.get("page").isdigit() else 1) # 獲取頁碼 page = paginator.get_page(current_page) # 獲取當前頁碼的所有數據 # 我們按照頁面顯示11個頁碼為例。 # 如果總頁碼大於11 if paginator.num_pages > 11: if current_page - 5 < 1: # 當前頁小於中間頁碼時 page_range = range(1, 12) elif current_page + 5 > paginator.num_pages: # 當前頁大於中間頁碼時 page_range = range(paginator.num_pages - 10, paginator.num_pages + 1) else: page_range = range(current_page - 5, current_page + 6) else: page_range = paginator.page_range
2. template（模板層）
{# 將之前的pagintor.page_range，改為page_range即可#} {% for num in page_range %} {% if current_page == num %} <li class="active"><a href="?page={{ num }}">{{ num }}</a></li> {% else %} <li><a href="?page={{ num }}">{{ num }}</a></li> {% endif %} {% endfor %}
三. 自定制分頁器
1. 自定制分頁器類
class Paginator: def __init__(self, current_page, all_count, per_page=10, max_page_num=11): """ 封裝分頁相關數據 :param current_page: 當前頁碼 :param all_count: 數據庫中的數據總條數 :param per_page: 每個頁面顯示的數據條數 :param max_page_num: 最多顯示的頁碼個數 :param num_pages: 通過總條數/每個頁面顯示的條數，求出總頁數 """ try: current_page = int(current_page) except Exception as e: current_page = 1 if current_page < 1: current_page = 1 self.current_page = current_page self.all_count = all_count self.per_page = per_page # 計算總頁數 num_pages, temp = divmod(all_count, per_page) if temp: num_pages += 1 self.num_pages = num_pages self.max_page_num = max_page_num # 11 self.page_count_half = int((self.max_page_num - 1) / 2) # 5 """ self.num_pages=100 per_page=8 current_page =1 [0:8] current_page =2 [8:16] current_page =3 [16:24] [(current_page-1)*per_page:current_page*per_page ] """ @property def start(self): return (self.current_page - 1) * self.per_page @property def end(self): return self.current_page * self.per_page def page_html(self): # 如果總頁數小於self.max_page_num(最多顯示的頁碼個數) if self.num_pages <= self.max_page_num: page_start = 1 page_end = self.num_pages + 1 else: # 如果當前頁碼<=頁面上最多顯示11/2個頁碼時 if self.current_page <= self.page_count_half: page_start = 1 page_end = self.max_page_num + 1 # 如果當前頁碼+最多顯示11/2 大於 總頁數時 elif self.current_page + self.page_count_half > self.num_pages: page_start = self.num_pages - self.max_page_num + 1 page_end = self.num_pages + 1 else: page_start = self.current_page - self.page_count_half page_end = self.current_page + self.page_count_half + 1 page_html_list = [] # 首頁 first_page = '<nav aria-label="Page navigation"><ul class="pagination"><li><a href="?page=1">首頁</a></li>' page_html_list.append(first_page) # 上一頁 if self.current_page <= 1: prev_page = '<li class="disabled"><a href="javascript:void(0);">上一頁</a></li>' else: prev_page = '<li><a href="?page=%s">上一頁</a></li>' % (self.current_page - 1, ) page_html_list.append(prev_page) # 顯示頁碼 for i in range(page_start, page_end): if self.current_page == i: temp = '<li class="active"><a href="?page=%s">%s</a></li>' % (i, i) else: temp = '<li><a href="?page=%s">%s</a></li>' % (i, i) page_html_list.append(temp) # 下一頁 if self.current_page >= self.num_pages: next_page = '<li class="disabled"><a href="javascript:void(0);">下一頁</a></li>' else: next_page = '<li><a href="?page=%s">下一頁</a></li>' % (self.current_page + 1) page_html_list.append(next_page) # 尾頁 last_page = '<li><a href="?page=%s">尾頁</a></li></ul></nav>' % self.num_pages page_html_list.append(last_page) return "".join(page_html_list)
2. 視圖層
class Index(View): def get(self, request): book_list = models.Book.objects.all() current_page = request.GET.get('page') paginator = Paginator(current_page, book_list.count(), 6, 11) book_list = book_list[paginator.start: paginator.end] return render(request, "index2.html", {"book_list": book_list, "paginator": paginator, "current_page": current_page})
3. 模板層
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title></title> <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"> </head> <body> <h3>書籍列表!!!</h3> <ul> {% for book in book_list %} <li>{{ book.title }} --- {{ book.price }}</li> {% endfor %} </ul> {{ paginator.page_html|safe }} </body> </html>
四. 自定制分頁器（終極版本）
跟上一版本的區別，主要是可以攜帶之前的參數了，這樣我們在后面做項目時，如果有復雜的過濾條件時，就可以輕松應對了。請參考下面的代碼：
1. 分頁器類
class Paginator: def __init__(self, request, current_page, all_count, per_page=10, max_page_num=13): """ 封裝分頁相關數據 :param current_page: 當前頁碼 :param all_count: 數據庫中的數據總條數 :param per_page: 每個頁面顯示的數據條數 :param max_page_num: 最多顯示的頁碼個數 :param num_pages: 通過總條數/每個頁面顯示的條數，求出總頁數 """ try: current_page = int(current_page) except Exception as e: current_page = 1 if current_page < 1: current_page = 1 self.current_page = current_page self.all_count = all_count self.per_page = per_page # 計算總頁數 num_pages, temp = divmod(all_count, per_page) if temp: num_pages += 1 self.num_pages = num_pages self.max_page_num = max_page_num # 11 self.page_count_half = int((self.max_page_num - 1) / 2) # 5 import copy self.url_args = copy.deepcopy(request.GET) print(self.url_args.urlencode()) """ self.num_pages=100 per_page=8 current_page =1 [0:8] current_page =2 [8:16] current_page =3 [16:24] [(current_page-1)*per_page:current_page*per_page ] """ @property def start(self): return (self.current_page - 1) * self.per_page @property def end(self): return self.current_page * self.per_page def page_html(self): # 如果總頁數小於self.max_page_num(最多顯示的頁碼個數) if self.num_pages <= self.max_page_num: page_start = 1 page_end = self.num_pages + 1 else: # 如果當前頁碼<=頁面上最多顯示11/2個頁碼時 if self.current_page <= self.page_count_half: page_start = 1 page_end = self.max_page_num + 1 # 如果當前頁碼+最多顯示11/2 大於 總頁數時 elif self.current_page + self.page_count_half > self.num_pages: page_start = self.num_pages - self.max_page_num + 1 page_end = self.num_pages + 1 else: page_start = self.current_page - self.page_count_half page_end = self.current_page + self.page_count_half + 1 page_html_list = [] # 首頁 self.url_args['page'] = 1 first_page = '<nav aria-label="Page navigation"><ul class="pagination"><li><a href="?%s">首頁</a></li>' % (self.url_args.urlencode()) page_html_list.append(first_page) # 上一頁 if self.current_page <= 1: prev_page = '<li class="disabled"><a href="javascript:void(0);">上一頁</a></li>' else: self.url_args['page'] = self.current_page - 1 prev_page = '<li><a href="?%s">上一頁</a></li>' % (self.url_args.urlencode(), ) page_html_list.append(prev_page) # 顯示頁碼 for i in range(page_start, page_end): self.url_args['page'] = i if self.current_page == i: temp = '<li class="active"><a href="?%s">%s</a></li>' % (self.url_args.urlencode(), i) else: temp = '<li><a href="?%s">%s</a></li>' % (self.url_args.urlencode(), i) page_html_list.append(temp) # 下一頁 if self.current_page >= self.num_pages: next_page = '<li class="disabled"><a href="javascript:void(0);">下一頁</a></li>' else: self.url_args['page'] = self.current_page + 1 next_page = '<li><a href="?%s">下一頁</a></li>' % (self.url_args.urlencode(), ) page_html_list.append(next_page) # 尾頁 self.url_args['page'] = self.num_pages last_page = '<li><a href="?%s">尾頁</a></li></ul></nav>' % self.url_args.urlencode() page_html_list.append(last_page) return "".join(page_html_list)
2. 視圖層
class Index(View): def get(self, request): book_list = models.Book.objects.all() current_page = request.GET.get('page') paginator = Paginator(request, current_page, book_list.count(), 6, 11) book_list = book_list[paginator.start: paginator.end] return render(request, "index2.html", {"book_list": book_list, "paginator": paginator, "current_page": current_page})
3. 模板層
同上面的模板層代碼。