上一篇中，我們已經打開了Django自帶的用戶認證模塊，并配置了數據庫連接，創建了相應的表，本篇我們將在Django自帶的用戶認證的基礎上，實現自己個性化的用戶登錄和注銷模塊。

首先，我們自己定義一個用戶登錄表單(forms.py):

from django import formsfrom django.contrib.auth.models import Userfrom bootstrap_toolkit.widgets import BootstrapDateInput, BootstrapTextInput, BootstrapUneditableInput class LoginForm(forms.Form):  username = forms.CharField(    required=True,    label=u"用戶名",    error_messages={'required': '請輸入用戶名'},    widget=forms.TextInput(      attrs={        'placeholder':u"用戶名",      }    ),  )    password = forms.CharField(    required=True,    label=u"密碼",    error_messages={'required': u'請輸入密碼'},    widget=forms.PasswordInput(      attrs={        'placeholder':u"密碼",      }    ),  )    def clean(self):    if not self.is_valid():      raise forms.ValidationError(u"用戶名和密碼為必填項")    else:      cleaned_data = super(LoginForm, self).clean()

我們定義的用戶登錄表單有兩個域username和password，這兩個域都為必填項。

接下來，我們定義用戶登錄視圖(views.py)，在該視圖里實例化之前定義的用戶登錄表單

from django.shortcuts import render_to_response,render,get_object_or_404 from django.http import HttpResponse, HttpResponseRedirect from django.contrib.auth.models import User from django.contrib import authfrom django.contrib import messagesfrom django.template.context import RequestContext from django.forms.formsets import formset_factoryfrom django.core.paginator import Paginator, PageNotAnInteger, EmptyPage from bootstrap_toolkit.widgets import BootstrapUneditableInputfrom django.contrib.auth.decorators import login_required from .forms import LoginForm def login(request):  if request.method == 'GET':    form = LoginForm()    return render_to_response('login.html', RequestContext(request, {'form': form,}))  else:    form = LoginForm(request.POST)    if form.is_valid():      username = request.POST.get('username', '')      password = request.POST.get('password', '')      user = auth.authenticate(username=username, password=password)      if user is not None and user.is_active:        auth.login(request, user)        return render_to_response('index.html', RequestContext(request))      else:        return render_to_response('login.html', RequestContext(request, {'form': form,'password_is_wrong':True}))    else:      return render_to_response('login.html', RequestContext(request, {'form': form,}))

該視圖實例化了之前定義的LoginForm，它的主要業務邏輯是：

1. 判斷必填項用戶名和密碼是否為空，如果為空，提示"用戶名和密碼為必填項”的錯誤信息

2. 判斷用戶名和密碼是否正確，如果錯誤，提示“用戶名或密碼錯誤"的錯誤信息