django-基于类的通用视图

所有视图继承自View类，例如，RedirectView用于HTTP重定向，TemplateView扩展基类使它能渲染模板。

ListView类：要在index.html中用列表显示对象

    <ul>
        {% for question in latest_question_list %}
            <li><a href="{% url 'polls:detail' question.id %}">{{ question.question_text }}</a></li>
        {% endfor %}
    </ul>    

改写前后urls.py------

前：

from django.urls import path
from . import views

app_name = 'polls'
urlpatterns = [
    path('', views.index, name='index')
]

后：

from django.urls import path
from . import views

app_name = 'polls'
urlpatterns = [
    path('', views.IndexView.as_view(), name='index')
]

改写前后Views.py----

前：

from django.shortcuts import render
from .models import Question

def index(request):
    latest_question_list = Question.objects.order_by('-pub_date')[:5]
    context = {'latest_question_list': latest_question_list}
    return render(request, 'polls/index.html', context)

后：

from django.views import generic

class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        return Question.objects.filter().order_by('-pub_date')[:5]

也可以把IndexView里的属性写到urls.py中：任何传递到 as_view()  的参数将覆盖在类上设置的属性

path('', views.IndexView.as_view(template_name='polls/index.html'), name='index'),

也可以没有get_queryset方法，但是需要指定model，如果不写上下文传递的对象默认为“object_list”

TemplateView类：没有动态数据，只显示模板about.html的视图

# some_app/views.py
from django.views.generic import TemplateView

class AboutView(TemplateView):
    template_name = "about.html"

# urls.py
from django.urls import path
from some_app.views import AboutView

urlpatterns = [
    path('about/', AboutView.as_view()),
]