@deprecate_current_app
@sensitive_post_parameters()
@csrf_protect
@never_cache
# 视图函数要渲染的模板位置（registration/login.html）
def login(request, template_name='registration/login.html',
     redirect_field_name=REDIRECT_FIELD_NAME,
     authentication_form=AuthenticationForm,
     extra_context=None, redirect_authenticated_user=False):
  """
  Displays the login form and handles the login action.
  """
  redirect_to = request.POST.get(redirect_field_name, request.GET.get(redirect_field_name, ''))
  if redirect_authenticated_user and request.user.is_authenticated:
    redirect_to = _get_login_redirect_url(request, redirect_to)
    if redirect_to == request.path:
      raise ValueError(
        "Redirection loop for authenticated user detected. Check that "
        "your LOGIN_REDIRECT_URL doesn't point to a login page."
      )
    return HttpResponseRedirect(redirect_to)
  elif request.method == "POST":
    form = authentication_form(request, data=request.POST)
    if form.is_valid():
      auth_login(request, form.get_user())
      return HttpResponseRedirect(_get_login_redirect_url(request, redirect_to))
  else:
    form = authentication_form(request)
  current_site = get_current_site(request)
  context = {
    'form': form,
    redirect_field_name: redirect_to,
    'site': current_site,
    'site_name': current_site.name,
  }
  if extra_context is not None:
    context.update(extra_context)
  return TemplateResponse(request, template_name, context)

from django.conf.urls import url
from . import views
from django.contrib.auth import views as auth_views
urlpatterns = [
  # 自定义登录
  # url(r'^login/$', views.user_login, name='user_login'),
  # django内置的登录
  url(r"^login/$", auth_views.login, name="user_login"),
]

{% extends "base.html" %}
{% block title %}登录{% endblock %}
{% block content %}
<div class="row text-center vertical-middle-sm">
 <h1>登录</h1>
 <p>请输入用户名和密码</p>
  <!--用具体的URL指明了数据的POST目标-->
 <form class="form-horizontal" action="{% url 'account:user_login' %}" method="post">
 {% csrf_token %}
    <!--每个表单元素在一对P标签内-->
    <!--{{ form.as_p }}-->
    <!--使用Bootstrap样式使得表单更美丽-->
    <div class="form-group">
  <label for="{{ form.username.id_for_label }}" class="col-md-5 control-label" style="color:red"><span class="glyphicon glyphicon-user"></span>Username</label>
  <div class="col-md-6 text-left">{{ form.username }}</div>
 </div>
 <div class="form-group">
  <label for="{{ form.password.id_for_label }}" class="col-md-5 control-label" style="color:blue"><span class="glyphicon glyphicon-floppy-open"></span>Password</label>
  <div class="col-md-6 text-left">{{ form.password }}</div>
 </div>
 <input type="submit" value="Login">
 </form>
</div>
{% endblock %}

# 登录后重定向到http://localhost:8000/blog/页面
LOGIN_REDIRECT_URL = '/blog/'

from django.conf.urls import url
from . import views
from django.contrib.auth import views as auth_views
urlpatterns = [
  # 自定义登录
  # url(r'^login/$', views.user_login, name='user_login'),
  # django内置的登录
  url(r"^login/$", auth_views.login, name="user_login"),
  url(r"^new-login/$", auth_views.login, {"template_name": "account/login.html"}),
]