django的用户form登录

{% if request.user.is_authenticated %}
             <div class="top">
   <div class="wp">
      <div class="fl">
         <p>服务电话：<b>33333333</b></p>
                 </div>
          <!--登录后跳转-->

         <div class="personal">
                         <dl class="user fr">
                             <dd>bobby<img class="down fr" src="../images/top_down.png"/></dd>
                             <dt><img width="20" height="20" src="../media/image/2016/12/default_big_14.png"/></dt>
                         </dl>
                         <div class="userdetail">
                           <dl>
                              <dt><img width="80" height="80" src="../media/image/2016/12/default_big_14.png"/></dt>
                              <dd>
                                  <h2>django</h2>
                                  <p>bobby</p>
                              </dd>
                             </dl>
                             <div class="btn">
                              <a class="personcenter fl" href="usercenter-info.html">进入个人中心</a>
                              <a class="fr" href="/logout/">退出</a>
                             </div>
                         </div>
                     </div>
                 </div>
</div>
             {% else %}
             <div class="top">
   <div class="wp">
      <div class="fl"><p>服务电话：<b>33333333</b></p></div>
      <!--登录后跳转-->
                     <a style="color:white" class="fr registerbtn" href="register.html">注册</a>
                     <a style="color:white" class="fr loginbtn" href="login.html">登录</a>
   </div>
</div>
         {% endif %}

<div class="fl form-box">
    <h2>帐号登录</h2>
    <form action="/login/" method="post" autocomplete="off">
        <input type=‘hidden‘ name=‘csrfmiddlewaretoken‘ value=‘mymQDzHWl2REXIfPMg2mJaLqDfaS1sD5‘ />
        <div class="form-group marb20 }{% if login_form.errors.username %} errorput {% endif %}">
            <label>用&nbsp;户&nbsp;名</label>
            <input name="username" id="account_l" type="text" placeholder="手机号/邮箱" />
        </div>
        <div class="form-group marb8 {% if login_form.errors.password %} errorput {% endif %}">
            <label>密&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;码</label>
            <input name="password" id="password_l" type="password" placeholder="请输入您的密码" />
        </div>
        <div class="error btns login-form-tips" id="jsLoginTips">{% for key,error in login_form.errors.items %}{{ error }}{% endfor %}{{ msg }}</div>
         <div class="auto-box marb38">

            <a class="fr" href="forgetpwd.html">忘记密码？</a>
         </div>
         <input class="btn btn-green" id="jsLoginBtn" type="submit" value="立即登录 > " />
    <input type=‘hidden‘ name=‘csrfmiddlewaretoken‘ value=‘5I2SlleZJOMUX9QbwYLUIAOshdrdpRcy‘ />
    {% csrf_token %}
    </form>
    <p class="form-p">没有慕学在线网帐号？<a href="register.html">[立即注册]</a></p>
</div>

from django.contrib.auth import authenticate,login

class LoginView(View):

    def get(self,request):
        return render(request, "login.html", {})

    def post(self,request):
        login_form = LoginForm(request.POST)
        if login_form.is_valid():
            user_name = request.POST.get(‘username‘, ‘‘)
            pass_word = request.POST.get(‘password‘, ‘‘)
            user = authenticate(username=user_name, password=pass_word)  # 验证这两个数据和数据库是否相同
            if user is not None:
                if user.is_active:
                    login(request, user)  # 调用该方法进行登录
                    return render(request, ‘index.html‘)
                else:
                    return render(request, ‘login.html‘)
            else:
                return render(request, "login.html", {‘msg‘: u‘用户名或者密码错误！‘})
        else:
            return render(request, "login.html", {‘login_form‘: login_form})

前提：登录的时候必须输入username和password来完成，如何通过邮箱以及username都能登录呢，django提供了一种方法，让我们可以自定义authenticate方法来完成登录，只需要在setting.py当中重载一个变量，

# Application definition
AUTHENTICATION_BACKENDS = (
    ‘users.views.CustomBackends‘,
)
在user的view中定义这个类：

from django.contrib.auth.backends import ModelBackend

from django.db.models import Q

class CustomBackends(ModelBackend):
    def authenticate(self, username=None, password=None, **kwargs):
        try:
            user = UserProfile.objects.get(Q(username=username)| Q(email=username))
            if user.check_password(password):
                return user
        except Exception as e:
            return None
form的用处：把用户提交过来的表单进行一部分预处理，只有处理通过才能进行下一步处理。
在userapp下建立一个forms.py文件，

from django import forms

class LoginForm(forms.Form):
    username = forms.CharField(required=True)
    password = forms.CharField(required=True,min_length=5)
注意：html页面的username和password字段名称必须和form里面的字段名称一样，实例化form的时候就已经对里面的字段都做了验证，只有form验证通过之后，才会到数据中查询是否正确