Django NoReverseMatch at/services/'services' 不是注册的命名空间

Question

我正在尝试显示一组按类别分类的图像。当用户单击类别名称时，页面应显示属于该类别的图像。我收到下一个浏览器错误:

NoReverseMatch at /services/
'services' is not a registered namespace

. . .

Error during template rendering

这些模型属于不同的应用程序，一个(包含类别模型)工作正常，而另一个(包含服务模型)只要我删除我需要的 html 内容就可以工作。请帮助我。

这是我的文件:

home_app/models.py

from django.db import models
from django.urls import reverse

class Category(models.Model):
    name=models.CharField(primary_key=True, max_length=50)
    slug=models.SlugField(unique=True, blank=True, null=True)
    image=models.ImageField(upload_to='category_home')
    description=models.CharField(max_length=100)
    content=models.TextField(max_length=500, default="Service")
    created=models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name = 'Category'
        verbose_name_plural = 'Categories'

    def __str__(self):
        return self.name

    def get_absolute_url(self):
        return reverse('services:services_by_category', args=[self.slug])

services_app/models.py

from django.db import models
from home_app.models import Category

class Services(models.Model):
    category=models.ForeignKey(Category, on_delete=models.CASCADE)
    title=models.CharField(max_length=50)
    completed=models.DateField(auto_now_add=False, null=True, blank=True)
    content=models.CharField(max_length=50, null=True, blank=True)
    image=models.ImageField(upload_to='services_services')
    created=models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name = 'Service'
        verbose_name_plural = 'Services'
    
    def __str__(self):
        return '%s de %s' % (self.category, self.title)

services_app/views.py

from django.shortcuts import render, get_object_or_404
from .models import Services
from home_app.models import Category

def service_list(request,category_slug=None):
    category = None
    categories = Category.objects.all()
    services = Services.objects.all()
    if category_slug:
        category = get_object_or_404(Category,slug=category_slug)
        services = services.filter(category=category)
    return render(request, 'services_app/services.html', {'categories':categories, 'category':category, 'services':services,})

services_app/urls.py

from django.urls import path
from services_app import views

urlpatterns = [
    path('', views.service_list, name='Services'),
    path('<slug:category_slug>', views.service_list, name='services_by_category'),
]

services_app/templates/services_app/services.html

    {% extends "home_app/base.html" %}   
    {% load static %}
    {% block content %}
    
    <!-- The app only works if I delete this section -->
    
    <div id="sidebar">
        <h3>Categories</h3>
            <ul>
            {% for c in categories %}
                <li>
               <h4><a href="{{ c.get_absolute_url }}">{{ c.name }}</a></h4>
                </li>
            {% endfor %}
            </ul>
    </div><br>
    <div>
        <h1>{% if category %}{{ category.name }}{% endif %}</h1>
        {% for service in services %}
            <img src="{{service.image.url}}">
        {% endfor %}
    </div>
{% endblock %}

还有我的主要网址:

from django.contrib import admin
from django.urls import path, include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', include('home_app.urls')),
    path('services/', include('services_app.urls')),
    path('contact/', include('contact_app.urls')),
]

Answer 1

只需更改 en models.py 中的以下内容:

def get_absolute_url(self):
    return reverse('services_by_category', args=[self.slug])

'因为您还没有定义命名空间服务。