视图newsletter.views.control_newsletter_edit没有返回HttpResponse对象。它没有返回任何东西

Question

这是我的urls.py：

from django.urls import path
from newsletter.views import control_newsletter, control_newsletter_list, control_newsletter_detail, control_newsletter_edit

urlpatterns = [
    path('newsletter/', control_newsletter, name='control_newsletter'),
    path('newsletter_list/', control_newsletter_list, name='control_newsletter_list'),
    path('newsletter_detail/<int:pk>/', control_newsletter_detail, name='control_newsletter_detail'),
    path('newsletter_edit/<int:pk>/', control_newsletter_edit, name='control_newsletter_edit'),]

这是我的view.py：

def control_newsletter_edit(request, pk):
    newsletter = get_object_or_404(Newsletter, pk=pk)
    if request.method == 'POST':

        form = NewsletterCreationForm(request.POST, instance=Newsletter)

        if form.is_valid():
            newsletter = form.save()

            if newsletter.status == 'Published':
                subject = newsletter.subject
                body = newsletter.body
                from_email = global_settings.EMAIL_HOST_USER
                for email in newsletter.email.all():
                    send_mail(subject=subject, from_email=from_email, recipient_list=[email], message=body,
                              fail_silently=True)
                messages.success(request, 'Your Changes Write Successfully.',
                                 'alert alert-success alert-dismissible')
            else:
                messages.warning(request, 'SomeThing Went Wrong..',
                                 'alert alert-warning alert-dismissible')
            return redirect('control_newsletter_detail', pk=newsletter.pk)

        else:
            form = NewsletterCreationForm(instance=newsletter)

            context = {
                'form': form,
            }

            return render(request, 'control_panel/control_newsletter.html', context)

当我尝试从这里访问newsletter_edit/1/时，在我的模板代码中：

<div class="col-sm-8">
            <div class="col-sm-2">
                <a href="{% url 'control_newsletter_edit' pk=newsletter.pk %}">
                    <button class="btn-success">Edit</button>
                </a>
            </div>

我面对这个错误：

ValueError at /panel/newsletter_edit/1/
The view newsletter.views.control_newsletter_edit didn't return an HttpResponse object. It returned None instead.

我一遍又一遍地检查我的urls.py和views.py，但是我找不到我的问题所在。有谁知道我为什么要面对这个错误吗？，另外，我很抱歉在我的问题中写错了。，如果你需要完整的views.py，请告诉我。

Answer 1

您的问题是if request.method == 'POST':，因为您可以看到，当请求方法是post时，您只返回一个模板，请确保在if条件之外返回一些内容