修改模型类HeroAdmin

@admin.register(Hero)
class HeroAdmin(admin.ModelAdmin):
    change_list_template = "entities/heroes_changelist.html"
    
    ...    # 此处原代码不动，只增加此前后代码
    
    def get_urls(self):
        urls = super().get_urls()
        my_urls = [
            path('immortal/', self.set_immortal),
            path('mortal/', self.set_mortal),
        ]
        return my_urls + urls
    def set_immortal(self, request):
        self.model.objects.all().update(is_immortal=True)
        self.message_user(request, "All heroes are now immortal")
        return HttpResponseRedirect("../")
    def set_mortal(self, request):
        self.model.objects.all().update(is_immortal=False)
        self.message_user(request, "All heroes are now mortal")
        return HttpResponseRedirect("../")
        

新增目录文件templates/Entities/change_form.html，Entities为应用名。change_form.html代码如下：

{% extends "admin/change_form.html" %}
{% load i18n admin_urls %}
{% block object-tools-items %}
    <li>
        <a href="{% url opts|admin_urlname:'history' original.pk|admin_urlquote %}" class="historylink">{% translate "History" %}</a>
    </li>
    <li>
        <a href="mylink/" class="historylink">My Link</a>
    </li>
    {% if has_absolute_url %}
        <li>
            <a href="{% url 'admin:view_on_site' content_type_id original.pk %}" class="viewsitelink">{% translate "View on site" %}</a>
        </li>
    {% endif %}
{% endblock %}

显示效果：