1.解决使用系统自带登录功能时，出现403错误的方法,注释如下代码

djg3->settings->MIDDLEWSRE:

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    # 提交时必须注释
    # 'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

2.用户没登录时，访问需要登录才能访问的html时，默认跳转的路径

djg3->settings->末尾添加

LOGIN_URL='/user/login/'

3.users->urls.py

from django.conf.urls import url
from django.contrib.auth.decorators import login_required

from user import views

urlpatterns=[
    # 登录
    url(r'^login/',views.login,name='login'),
    # 注册
    url(r'^register/',views.register,name='register'),
    # login_required  登录后才能使用的路由
    # 首页
    url(r'^index/',login_required(views.index),name='index'),
    # 注销
    url(r'^logout/',login_required(views.logout),name='logout'),
]

4.users->views.py

from django.contrib import auth
from django.contrib.auth.models import User
from django.http import HttpResponseRedirect, HttpResponse
from django.shortcuts import render
from django.urls import reverse

from users.forms import UserForm, LoginForm


def register(request):
    if request.method=='GET':
        return render(request,'register.html')
    if request.method=='POST':
        #校验页面中传递的参数，是否填写完整
        form = UserForm(request.POST)
        #is_valid():判断表单验证是否通过
        if form.is_valid():
            # 获取校验后的用户和密码
            username=form.cleaned_data.get('username')
            password1 = form.cleaned_data.get('password1')
            password2 = form.cleaned_data.get('password2')
            # 判断密码是否相同
            # 创建普通用户creat_user,创建超级管理员用户create_superuser
            User.objects.create_user(username=username,password=password1)
            # 实现跳转
            return HttpResponseRedirect(reverse('users:login'))
        else:
            return render(request,'register.html',{'form':form})

def login(request):
    if request.method=='GET':
        return render(request,'login.html')
    if request.method=='POST':
        #表单验证，用户名和密码是否填写，校验用户名是否注册
        form =LoginForm(request.POST)
        if form.is_valid():
            # 校验用户名和密码，判断返回的对象是否为空，如果不为空，则为user对象

            user=auth.authenticate(username=form.cleaned_data['username'],
                                   password=form.cleaned_data['password'])
            if user:
                # 用户名和密码都是正确的，则登录
                #进入登录状态，满足login_required要求
                auth.login(request,user)
                #跳转页面
                return HttpResponseRedirect(reverse('users:index'))
            else:
                # 密码不正确
                return render(request,'login.html',{'error':'密码错误'})
        else:
            return render(request,'login.html',{'form':form})


def index(request):
    if request.method=='GET':
        return render(request,'index.html')


def logout(request):
    if request.method=='GET':
        # 注销
        #取消login_required的登录状态,进入未登录状态
        auth.logout(request)
        #跳转页面
        return HttpResponseRedirect(reverse('users:login'))

5.users->forms

'''
导入规则顺序
1.新引入python自带的库
2.引入地方
3.引入自定义的
'''
from django import forms
from django.contrib.auth.models import User


class UserForm(forms.Form):
    username=forms.CharField(required=True,
                             max_length=5,
                             min_length=2,
                             error_messages={
                                 'required':'用户名必填',
                                 'max_length':'用户名不能超过7个字符',
                                 'min_length':'用户名至少两个字符'
                             })
    password1=forms.CharField(required=True,
                              min_length=6,
                              error_messages={
                                  'required':'密码必填',
                                  'min_length':'密码不能少于6位'
                              })
    password2=forms.CharField(required=True,
                              min_length=6,
                              error_messages={
                                  'required':'确认密码必填',
                                  'min_length':'确认密码不能少于6个'
                              })


    def clean(self):
        # 校验用户名是否已经注册过
        user=User.objects.filter(username=self.cleaned_data.get('username'))
        if user:
            raise forms.ValidationError({'username':'用户名已存在'})

        # 校验密码和确认密码是否相同
        if self.cleaned_data.get('password1')!=self.cleaned_data.get('password2'):
            raise forms.ValidationError({'password2':'两次密码不一致'})
        return self.cleaned_data


class LoginForm(forms.Form):
    username = forms.CharField(required=True,
                               max_length=5,
                               min_length=2,
                               error_messages={
                                   'required': '用户名必填',
                                   'max_length': '用户名不能超过7个字符',
                                   'min_length': '用户名至少两个字符'
                               })
    password = forms.CharField(required=True,
                                min_length=6,
                                error_messages={
                                    'required': '密码必填',
                                    'min_length': '密码不能少于6位'
                                })
    def clean(self):
        user = User.objects.filter(username=self.cleaned_data['username'])
        if not user:
            raise forms.ValidationError({'username': '用户名不存在，请注册'})
        return self.cleaned_data

6.templates web页面

1）base.html 父模板

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>
        {% block title %}
        {% endblock %}
    </title>
</head>
    {% block extCss %}
    {% endblock %}

    {% block extJs %}
    {% endblock %}
<body>
    {% block content %}
    {% endblock %}
</body>
</html>

2)base_main.html 设置js

{% extends 'base.html' %}

{% block extJs %}
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"type="text/javascript"></script>
{% endblock %}

3)login 登录页面

{% extends 'base_main.html' %}

{% block title %}
登录
{% endblock %}

{% block content %}

    <form action="" method="post">
        {{form.errors.username}}
        <p>姓名：<input type="text" name="username"></p>
        {{form.errors.password}}
        <p>密码：<input type="password" name="password"></p>
        <input type="submit" value="登录">

    </form>
{% endblock %}

4)register.html 注册页面

{% extends 'base_main.html' %}

{% block title %}
登录
{% endblock %}

{% block content %}

    <form action="" method="post">
        {{form.errors.username}}
        <p>姓名：<input type="text" name="username"></p>
        {{form.errors.password}}
        <p>密码：<input type="password" name="password"></p>
        <input type="submit" value="登录">

    </form>
{% endblock %}

5)index.html 首页

{% extends 'base_main.html' %}
{% block title %}
    首页
{% endblock %}
{% block content %}
    <p>我是首页，需要登录才能访问</p>
    <p><a href="{% url 'users:logout' %}">注销</a></p>
{% endblock %}