Question

我正在尝试构建一个登录页面。我正在运行Django 1.6.1。我在很大程度上遵循了www.fir3net.com/Django/django.html上的教程。为方便起见，我会在这里重新发布很多内容。

错误讯息：

Request Method: GET
Request URL: http://127.0.0.1:8000/login/

Database In Use: SQLite3 

Django Version: 1.6.1
Python Version: 2.7.4
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'django.contrib.contenttypes',
 'bookmarks')
Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.auth.middleware.RemoteUserMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware')


Traceback:
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
  114.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/tatenda/Documents/Programming/Django/Progs/django_bookmarks/bookmarks/views.py" in login_user
  17.   username = request.POST['username']
File "/usr/local/lib/python2.7/dist-packages/django/utils/datastructures.py" in __getitem__
  301.             raise MultiValueDictKeyError(repr(key))

Exception Type: MultiValueDictKeyError at /login/
Exception Value: "'username'"

查看代码（我知道这里调用的几个导入函数对我当前的问题是多余的。大多数情况下，它们都是冗余代码，因为我们试图按照之前的教程来解决这个问题）：

from django.http import*
from django.shortcuts import render_to_response, redirect
from django.template import RequestContext
from django.template import Context
from django.template.loader import get_template
from django.http import HttpResponse, Http404
from django.contrib.auth.models import User
from django.contrib.auth import authenticate, login, logout
from django.views.decorators.csrf import csrf_exempt, csrf_protect
from django.contrib.auth.decorators import login_required

def login_user(request):

    username = password = ''
    username = request.POST['username']
    password = request.POST['password']
    user = authenticate(username=username, password = password)
    if user is not None:
        if user.is_active:
            login(request, user)
            return HttpResponseRedirect('/main_page/')
    return render_to_response('base.html', context_instance = RequestContext(request))

@login_required(login_url = '/login/')
def main_page(request):
    template = get_template('main_page.html')
    variables = Context ({
        'head_title':'Django Bookmarks',
        'page_title':'Welcome to Django Bookmarks',
        'page_body':'Where you store and share bookmarks!'
    })
    output = template.render(variables)
    return HttpResponse(output)

def user_page(request, username):
    try:
        user = User.objects.get(username=username)
    except:
        raise Http404('Requested user not found.')

    bookmarks = user.bookmark_set.all()
    template = get_template('user_page.html')
    variables = Context({
        'username':username,
        'bookmarks': bookmarks
    })
    output = template.render(variables)
    return HttpResponse(output)

@csrf_exempt
def login_page(request):

    username = request.POST['username']
    password = request.POST['password']
    user = authenticate(username=username, password=password)
    if user is not None:
        if user.is_active:
            login(request,user)
            template = get_template('main_page.html')
            variables = Context ({
                'head_title':'Django Bookmarks',
                'page_title':'Welcome to Django Bookmarks',
                'page_body':'Where you store and share bookmarks!'
            })
            output = template.render(variables)
            return HttpResponse(output)
        else:
            raise Http404('Disabled account, please contact administrator.')
    else:
        raise Http404('Invalid login.')

来自urls.py文件的信息：

from django.conf.urls import patterns, include, url
from django.contrib import admin
from bookmarks.views import*

admin.autodiscover()

urlpatterns = patterns('',
    (r'^$', main_page),
    (r'^user/(\w+)/$', user_page),
    url(r'^login/$', login_user),
)

用于创建登录页面的基本模板（该文件名为base.html）：
注意 - CSS样式是基于bootstrap的

<!DOCTYPE html>
<html>
    <head>
        {% block head %}
            <link rel = "stylesheet" href = "style.css" />
            <title> {% block title %}{% endblock %} - My Webpage</title></div>
        {% endblock %}
    </head>
    <body>
        <div id = "content">{% block content %}{% endblock %}</div>
        <div id = "footer">
            {% block footer %}
                &copy; Copyright 2011 by <a href="http://domain.invalid/">you</a>
            {% endblock %}
        </div>
    </body>
</html>

登录页面的HTML代码（该文件名为login.html）：

{% extends "base.html" %}
{% block main %}
    <div id = "login">
        <form class = "form-horizontal" name = "LoginForm" action = "/login/" method = "post">
        {% csrf_token %}
        {% if next %}
            <input type = "hidden" name = "next" value = "{{ next }}" />
        {% endif %}
        <div class = "control-group">
            <label class = "control-label" for = "username">Username</label>
            <div class = "controls">
                <input type = "text" id = "username" placeholder = "Username">
            </div>
        </div>
        <div class = "control-group">
            <label class = "control-label" for = "password">Password</label>
            <div class = "controls">
                <input type = "password" name = "password" id = "password" placeholder = "Password">
            </div>
        </div>
        <div class = "control-group">
            <div class = "controls">
                <button type = "submit" class = "btn">Login</button>
            </div>
        </div>
        </form>
    </div>
{% endblock %}

Answer 1

我遇到了同样的错误，我做了这个并且有效。变化：

username = request.POST['username']
password = request.POST['password']

为：

username = request.POST.get('username')
password = request.POST.get('password')

以上处理可能导致的POST和GET方法。我希望这会有所帮助。

Answer 2

当请求解析为包含@login_required装饰器的视图时，如果用户未登录，请求将重定向到指定的URL。因此，尝试解析main_page视图登录后，用户的浏览器会向GET发出/login/请求。但是，处理该URL的视图假定POST请求：

username = request.POST['username']
password = request.POST['password']

通常的做法是遵循在视图中使用表单的一般模式： https://docs.djangoproject.com/en/dev/topics/forms/#using-a-form-in-a-view

具体来说，请检查request.method属性，以便您可以对GET请求采取适当的行为并呈现表单。或者使用built-in views，它们很容易使用。

Answer 3

我可以通过遵循@ Emack333来抑制错误，但是，views.py上的代码无法正常工作，然后经过仔细检查，我发现错误不在视图文件上，而是在HTML方面。

之所以产生此错误，是因为HTML输入标签上的name属性不匹配，在您的情况下，这是缺少name attr。

<input type = "text" id = "username" placeholder = "Username" name="username">

Answer 4

真正的问题是模板中的表单。

您需要使用'name ='属性而不是'id ='属性来分配密钥名称。

我刚刚为自己的项目解决了这个问题，并意识到这是罪魁祸首。

在登录页面上的POST请求之后在Django中生成的MultiValueDictKeyError

4 个答案: