python之未显示 Django CreateView 成功消息

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' 

请您参考如下方法:

为类 CreateRedirect 继承 SuccessMessageMixin，如下所示:

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