基于python框架django开发在线投票系统

from django.shortcuts import render # Create your views here. from django.http import HttpResponse from .models import Question, Choice # from django.template import loader from django.shortcuts import render from django.shortcuts import get_object_or_404 from django.http import HttpResponseRedirect from django.urls import reverse from django.views import generic from django.utils import timezone #views实际上是一个控制器，控制你前端要显示什么，MTV =MVC，接收urls传来的指令 # def index(request): # return HttpResponse('Hello 222,world. You\'re at the polls index.--邹涛') # def index(request): # #order_by : 倒序：- 正序：不加-即可。 0-5条数据 # latest_question_list = Question.objects.order_by('-pub_date')[:5] # # # output = '<br/> '.join([q.question_text for q in latest_question_list]) # return HttpResponse(output) #写了html以后这里引入，常规的函数方式： # def index(request): # #获取数据然后排序，显示前5条数据 # latest_question_list = Question.objects.order_by('-pub_date')[:5] # #templates是django系统下的，默认自动去到该路径下。注释的方法一 # # template = loader.get_template('polls/index.html') # context = { # 'latest_question_list':latest_question_list, # } # #render 表示django渲染（=显示）模板，需要获得参数context上下文 # # return HttpResponse(template.render(context,request)) # #方法二：django提供了最直接的方式，render渲染方式。 # return render(request,'polls/index.html',context) #面向对象OOP方式来写index页：通用View结尾 class IndexView(generic.ListView): """固定名称，来自于listview下的""" template_name = 'polls/index.html' context_object_name = 'latest_question_list' """也是固定用法函数名""" def get_queryset(self): return Question.objects.order_by('-pub_date')[:5] #详情页面--开始使用渲染传到前端_更改详情页面 # def detail(request, question_id): # question = get_object_or_404(Question, pk=question_id) # return render(request, 'polls/detail.html',{'question':question}) #面向对象OOP方式来写详情页：继承 class DetailView(generic.DetailView): model = Question template_name = 'polls/detail.html' #问题记录发布时间要小于等于当前时间 def get_queryset(self): return Question.objects.filter(pub_date__lte=timezone.now()) #结果页面 # def results(request,question_id): # response = "You're looking at question--—— %s." # return HttpResponse(response % question_id) #渲染版 # def results(request, question_id): # question = get_object_or_404(Question, pk=question_id) # return render(request, 'polls/results.html', {'question': question}) #面向对象OOP版来写结果页：继承datailview class ResultsView(generic.DetailView): model = Question template_name = 'polls/results.html' #投票页==添加到urls里面 # def vote(request,question_id): # return HttpResponse("You're looking at question %s."%question_id) def vote(request, question_id): #固定写法404，如果页面不存在，自动返回404页面。而不是直接报错 question = get_object_or_404(Question, pk=question_id) try: selected_choice = question.choice_set.get(pk=request.POST['choice']) except (KeyError,Choice.DoesNotExist): return render(request, 'polls/detail.html',{ 'question': question, 'error_message': "亲，还没选择哟！", }) else: selected_choice.votes += 1 selected_choice.save() return HttpResponseRedirect(reverse('polls:results', args=(question_id,)))