9.18 關於分頁的方法
阿新 • • 發佈：2018-09-18
view init efi 按鈕 一半 obj def books dep
2018-9-18 17:38:24
數據比較多少的時候需要分頁!
所有就引出了分頁 根據if 判斷分頁!邏輯很重要!但牽扯到的都是基礎知識
先放上原始版的views 的功能代碼
明天再看下午內容!
from django.shortcuts import render # Create your views here. from app01 import models def books(request): # 從URL取參數 page_num = request.GET.get("page") print(page_num, type(page_num))# 總數據是多少 total_count = models.Book.objects.all().count() # # 每一頁顯示多少條數據 # per_page = 10 # # # 總共需要多少頁碼來展示 # total_page, m = divmod(total_count, per_page) # if m: # total_page += 1 # try: # page_num = int(page_num) # # 如果輸入的頁碼數超過了最大的頁碼數，默認返回最後一頁# if page_num > total_page: # page_num = total_page # except Exception as e: # # 當輸入的頁碼不是正經數字的時候 默認返回第一頁的數據 # page_num = 1 # # # 定義兩個變量保存數據從哪兒取到哪兒 # data_start = (page_num-1)*10 # data_end = page_num*10 # # # 頁面上總共展示多少頁碼 # max_page = 11# if total_page < max_page: # max_page = total_page # # half_max_page = max_page // 2 # # 頁面上展示的頁碼從哪兒開始 # page_start = page_num - half_max_page # # 頁面上展示的頁碼到哪兒結束 # page_end = page_num + half_max_page # # 如果當前頁減一半 比1還小 # if page_start <= 1: # page_start = 1 # page_end = max_page # # 如果 當前頁 加 一半 比總頁碼數還大 # if page_end >= total_page: # page_end = total_page # page_start = total_page - max_page +1 # # all_book = models.Book.objects.all()[data_start:data_end] # # # 自己拼接分頁的HTML代碼 # html_str_list = [] # # 加上第一頁 # html_str_list.append(‘<li><a href="/books/?page=1">首頁</a></li>‘) # # # 判斷一下 如果是第一頁，就沒有上一頁 # if page_num <= 1: # html_str_list.append(‘<li class="disabled"><a href="#"><span aria-hidden="true">«</span></a></li>‘.format(page_num-1)) # else: # # 加一個上一頁的標簽 # html_str_list.append(‘<li><a href="/books/?page={}"><span aria-hidden="true">«</span></a></li>‘.format(page_num-1)) # # for i in range(page_start, page_end+1): # # 如果是當前頁就加一個active樣式類 # if i == page_num: # tmp = ‘<li class="active"><a href="/books/?page={0}">{0}</a></li>‘.format(i) # else: # tmp = ‘<li><a href="/books/?page={0}">{0}</a></li>‘.format(i) # # html_str_list.append(tmp) # # # 加一個下一頁的按鈕 # # 判斷，如果是最後一頁，就沒有下一頁 # if page_num >= total_page: # html_str_list.append(‘<li class="disabled"><a href="#"><span aria-hidden="true">»</span></a></li>‘) # else: # html_str_list.append(‘<li><a href="/books/?page={}"><span aria-hidden="true">»</span></a></li>‘.format(page_num+1)) # # 加最後一頁 # html_str_list.append(‘<li><a href="/books/?page={}">尾頁</a></li>‘.format(total_page)) # # page_html = "".join(html_str_list) # # 調用一個類 from utils.mypage import Page page_obj = Page(page_num, total_count, per_page=10, url_prefix="/books/", max_page=9,) ret = models.Book.objects.all()[page_obj.start:page_obj.end] page_html = page_obj.page_html() return render(request, "books.html", {"books": ret, "page_html": page_html}) def depts(request): # 從URL取參數 page_num = request.GET.get("page") print(page_num, type(page_num)) # 總數據是多少 total_count = models.Dept.objects.all().count() from utils.mypage import Page page_obj = Page(page_num, total_count, per_page=10, url_prefix="/depts/", max_page=11, ) ret = models.Dept.objects.all()[page_obj.start:page_obj.end] print(ret) page_html = page_obj.page_html() return render(request, "dept.html", {"depts": ret, "page_html": page_html})
再放上 直接 封裝一個類 實現功能!! 面向對象 封裝!
class Page(): def __init__(self, page_num, total_count, url_prefix, per_page=10, max_page=11): """ :param page_num: 當前頁碼數 :param total_count: 數據總數 :param url_prefix: a標簽href的前綴 :param per_page: 每頁顯示多少條數據 :param max_page: 頁面上最多顯示幾個頁碼 """ self.url_prefix = url_prefix self.max_page = max_page # 每一頁顯示多少條數據 # 總共需要多少頁碼來展示 total_page, m = divmod(total_count, per_page) if m: total_page += 1 self.total_page = total_page try: page_num = int(page_num) # 如果輸入的頁碼數超過了最大的頁碼數，默認返回最後一頁 if page_num > total_page: page_num = total_page except Exception as e: # 當輸入的頁碼不是正經數字的時候 默認返回第一頁的數據 page_num = 1 self.page_num = page_num # 定義兩個變量保存數據從哪兒取到哪兒 self.data_start = (page_num - 1) * 10 self.data_end = page_num * 10 # 頁面上總共展示多少頁碼 if total_page < self.max_page: self.max_page = total_page half_max_page = self.max_page // 2 # 頁面上展示的頁碼從哪兒開始 page_start = page_num - half_max_page # 頁面上展示的頁碼到哪兒結束 page_end = page_num + half_max_page # 如果當前頁減一半 比1還小 if page_start <= 1: page_start = 1 page_end = self.max_page # 如果 當前頁 加 一半 比總頁碼數還大 if page_end >= total_page: page_end = total_page page_start = total_page - self.max_page + 1 self.page_start = page_start self.page_end = page_end @property def start(self): return self.data_start @property def end(self): return self.data_end def page_html(self): # 自己拼接分頁的HTML代碼 html_str_list = [] # 加上第一頁 html_str_list.append(‘<li><a href="{}?page=1">首頁</a></li>‘.format( self.url_prefix)) # 判斷一下 如果是第一頁，就沒有上一頁 if self.page_num <= 1: html_str_list.append(‘<li class="disabled"><a href="#"><span aria-hidden="true">«</span></a></li>‘.format(self.page_num-1)) else: # 加一個上一頁的標簽 html_str_list.append(‘<li><a href="{}?page={}"><span aria-hidden="true">«</span></a></li>‘.format( self.url_prefix, self.page_num-1)) for i in range(self.page_start, self.page_end+1): # 如果是當前頁就加一個active樣式類 if i == self.page_num: tmp = ‘<li class="active"><a href="{0}?page={1}">{1}</a></li>‘.format(self.url_prefix, i) else: tmp = ‘<li><a href="{0}?page={1}">{1}</a></li>‘.format( self.url_prefix, i) html_str_list.append(tmp) # 加一個下一頁的按鈕 # 判斷，如果是最後一頁，就沒有下一頁 if self.page_num >= self.total_page: html_str_list.append(‘<li class="disabled"><a href="#"><span aria-hidden="true">»</span></a></li>‘) else: html_str_list.append(‘<li><a href="{}?page={}"><span aria-hidden="true">»</span></a></li>‘.format( self.url_prefix, self.page_num+1)) # 加最後一頁 html_str_list.append(‘<li><a href="{}?page={}">尾頁</a></li>‘.format( self.url_prefix, self.total_page)) page_html = "".join(html_str_list) return page_html
9.18 關於分頁的方法