未显示 Django CreateView 成功消息

Django CreateView success message not shown

我有一个 CreateView 和一个 UpdateView,两者都有成功消息。但是,只有 UpdateView 成功消息有效,而 CreateView 消息不显示。为什么会这样?

from django.contrib.messages.views import SuccessMessageMixin
 class CreateRedirect (CreateView):
        model = MarketingRedirect
        template_name = 'marketing_redirect/create_redirect.html'
        success_url = reverse_lazy('backend_redirect')
        fields = ['redirect_from', 'redirect_to']
        success_message = "Redirect successfully created!"


    class EditRedirect(SuccessMessageMixin, UpdateView):
        model = MarketingRedirect
        fields = ['redirect_from', 'redirect_to']
        template_name = 'marketing_redirect/edit_redirect.html'
        context_object_name = 'redirect'
        success_url = reverse_lazy('backend_redirect')
        success_message = 'Review successfully updated'

继承SuccessMessageMixin for class CreateRedirect 如下图:

class CreateRedirect(SuccessMessageMixin, CreateView):
    ....