django2.0入门教程第四节
继上篇 django2.0入门教程第三节，介绍了django2.0的视图views和模板template, 本节介绍如何在前台进行投票。
构建一个简单的表单提交页
polls/templates/polls/detail.html
<h1>{{ question.question_text }}</h1>
{% if error_message %}<p><strong>{{ error_message }}</strong></p>{% endif %}
<form action="{%url 'polls:vote' question.id %}" method="post">
{% csrf_token %}
{% for choice in question.choice_set.all %}
<input id="choice{{ forloop.counter }}" type="radio" name="choice" value="{{ choice.id }}">
<label for="choice{{ forloop.counter }}">{{ choice.choice_text }}</label><br />
{% endfor %}
<br />
<input type="submit" name="" id="" value="投票" />
</form>代码解析：
- form表单提交的url为
{%url 'polls:vote' question.id %}, 即表示访问polls/views.py的vote方法，并携带问题id作为参数。 - 将问题的相关选项遍历，以单选框显示
- form表单用post方式提交数据
配置url
polls/urls.py
path('<int:question_id>/vote/', views.vote, name='vote'),投票页面截图 http://127.0.0.1:8000/polls/1/ ：
vote.png
视图层处理提交结果
polls/views.py
from django.shortcuts import render, get_object_or_404
from django.http import HttpResponse, HttpResponseRedirect
from django.urls import reverse
from .models import Question, Choice
# ...
def vote(request, question_id):
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': "必须选择一个选项",
})
else:
selected_choice.votes += 1
selected_choice.save()
return HttpResponseRedirect(reverse('polls:results', args=(question.id,)))代码解析：
request.POST['choice']接收表单页面提交的数据- 将投票次数加1，并更新数据库
显示投票结果
polls/views.py
from django.shortcuts import render, get_object_or_404
# ...
def results(request, question_id):
question = get_object_or_404(Question, pk=question_id)
return render(request, 'polls/results.html', {'question': question})results.html
<h1>{{ question.question_text }}</h1>
<ul>
{% for choice in question.choice_set.all %}
<li>{{ choice.choice_text }} -- {{choice.votes}}</li>
{% endfor %}
</ul>
<a href="{% url 'polls:detail' question.id %}">再投一次？</a>提交结果页面 http://127.0.0.1:8000/polls/1/results/
result.png
优化url和view写法
另一种写法：
将主键id代替question_id
polls/urls.py
#_*_coding:utf8_*_
from django.urls import path
from . import views
app_name = 'polls'
urlpatterns = [
path('', views.IndexView.as_view(), name='index'),
path('<int:pk>/', views.DetailView.as_view(), name='detail'),
path('<int:pk>/results/', views.ResultsView.as_view(), name='results'),
path('<int:question_id>/vote/', views.vote, name='vote'),
]使用
<pk>代替<question_id>会更加灵活，<pd>代表主键
相应的视图也需要修改成另一种写法，vote方法保持原样，用于比较两种写法的不同
polls/views.py
#_*_coding:utf8_*_
from django.shortcuts import render, get_object_or_404
from django.http import HttpResponseRedirect
from django.urls import reverse
from django.views import generic
from .models import Question, Choice
class IndexView(generic.ListView):
template_name = 'polls/index.html'
context_object_name = 'latest_question_list'
def get_queryset(self):
return Question.objects.order_by('-pub_date')[:5]
class DetailView(generic.DetailView):
model = Question
template_name = 'polls/detail.html'
class ResultsView(generic.DetailView):
model = Question
template_name = 'polls/results.html'
def vote(request, question_id):
# ...入门教程不会对代码进入深入的讲解，先大致了解其作用即可，后续再逐个模块进行解析
源码下载
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原始发表：2018.01.05 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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