我正在使用 Django 開(kāi)發(fā)電子商務(wù)網(wǎng)站。目前正在開(kāi)發(fā)我第一次在 django 中使用 session 的購(gòu)物車(chē)應(yīng)用程序。我在設(shè)置和檢索打印時(shí)為空的會(huì)話(huà)數(shù)據(jù)時(shí)遇到問(wèn)題。PS：會(huì)話(huà)中的數(shù)據(jù)將用于為用戶(hù)檢索購(gòu)物車(chē)或更新購(gòu)物車(chē)（如果購(gòu)物車(chē)是作為訪(fǎng)問(wèn)者創(chuàng)建的）。無(wú)法檢索會(huì)話(huà)數(shù)據(jù)導(dǎo)致每次刷新瀏覽器時(shí)都會(huì)創(chuàng)建一個(gè)新會(huì)話(huà)。設(shè)置.PYINSTALLED_APPS = [    'django.contrib.admin',    'django.contrib.auth',    'django.contrib.contenttypes',    'django.contrib.sessions',    'django.contrib.messages',    'django.contrib.staticfiles',    # user apps    'carts',    'products',    'search',    'tags',    # 3rd class app    'bootstrap4',]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.messages.middleware.MessageMiddleware',    'django.middleware.clickjacking.XFrameOptionsMiddleware',]購(gòu)物車(chē)APP模型.PYfrom django.conf import settingsfrom django.db import modelsfrom products.models import ProductUser = settings.AUTH_USER_MODELclass CartManager(models.Manager):    def new(self, user=None):        user_obj = None        if user is not None:            if user.is_authenticated:                user_obj = user        return self.model.objects.create(user=user_obj)class Cart(models.Model):    user        = models.ForeignKey(User, null=True, blank=True, on_delete=models.DO_NOTHING)    products    = models.ManyToManyField(Product, blank=True)    total       = models.DecimalField(default=0.00, max_digits=100, decimal_places=2)    timestamp   = models.DateTimeField(auto_now_add=True)    updated     = models.DateTimeField(auto_now=True)    objects = CartManager()    def __str__(self):        return str(self.id)