运行服务器上的Django E.408，E.409和E.410错误

Question

我正在使用virtualenv安装一个新的Django项目，所有方法都正常。我的Python版本是3.7.3，而django是2.2.3。

如果我使用python manage.py runserver，则出现以下错误：

?: (admin.E408)'django.contrib.auth.middleware.AuthenticationMiddleware' must be in MIDDLEWARE in order to use the admin application.
?: (admin.E409) 'django.contrib.messages.middleware.MessageMiddleware' must be in MIDDLEWARE in order to use the admin application.
?: (admin.E410) 'django.contrib.sessions.middleware.SessionMiddleware' must be in MIDDLEWARE in order to use the admin application.

这是我的settings.py，您可以看到那里有那些中间件。

"""
Django settings for fcc_new project.

Generated by 'django-admin startproject' using Django 1.9.4.

For more information on this file, see
https://docs.djangoproject.com/en/1.9/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/1.9/ref/settings/
"""

import os

# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/1.9/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = MY KEY goes here

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

MIDDLEWARE_CLASSES = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'fcc_new.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'fcc_new.wsgi.application'


# Database
# https://docs.djangoproject.com/en/1.9/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': os.path.join(BASE_DIR, 'db.sqlite3'),
    }
}


# Password validation
# https://docs.djangoproject.com/en/1.9/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/1.9/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/1.9/howto/static-files/

STATIC_URL = '/static/'

我尝试重新安装，检查版本，并将“ MIDDLEWARE_CLASSES”更改为“ MIDDLEWARE”。什么都没用。谁能找到问题所在？

Answer 1

在Django 2.2.3中，使用变量MIDDLEWARE而非MIDDLEWERE_CLASSES来激活设置中的中间件，请检查文档here。

因此，只需将settings.py中的变量从MIDDLEWARE_CLASSES更改为MIDDLEWARE 。

此问题最有可能是由于使用全局版本{2的django软件包创建一个项目，然后使用具有本地manage.py runserver>的virtualenv运行django>导致的= 2

Answer 2

如图所示更改setting.py Change setting.py

# MIDDLEWARE_CLASSES = [
MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    # 'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

另请参阅：From CSDN

Answer 3

1）转到项目的settings.py

2）从MIDDLEWARE_CLASSES切下这三行：

    'django.contrib.sessions.middleware.SessionMiddleware', 
    'django.contrib.messages.middleware.MessageMiddleware', 
    'django.contrib.auth.middleware.AuthenticationMiddleware',

3）现在将下面给出的代码粘贴在MIDDLEWARE_CLASSES之后：

MIDDLEWARE = [
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
]

看起来像这样：

Answer 4

重命名settings.py中的变量，或添加此变量：

MIDDLEWARE = MIDDLEWARE_CLASSES

发送至settings.py 因为新的Django会根据如下检查触发上述错误：

if not _contains_subclass(
   'django.contrib.auth.middleware.AuthenticationMiddleware', 
   settings.MIDDLEWARE
):
   errors.append(checks.Error( ...