存储复选框信息的最佳方法是什么？

Question

我在class ActivityGroupInline(InlineFormSet): model = models.ActivityGroup fields = ['events',] can_delete = False extra = 0 @property def widgets(self): return { 'events': widgets.CheckboxSelectMultiple(), } def get_factory_kwargs(self): kwargs = super().get_factory_kwargs() kwargs.update({ 'widgets': self.widgets, }) return kwargs class ActivityGroupEventLink(NamedFormsetsMixin, UpdateWithInlinesView): model = models.Container fields = [] template_name = 'main/link_activitygroupsevents.html' success_url = reverse_lazy('dashboard') inlines = [ActivityGroupInline,] inlines_names = ['activitygroup_inline',] def get_object(self, queryset=None): return models.Container.objects.first() def get_context_data(self, *args, **kwargs): context = super().get_context_data(*args, **kwargs) context['breadcrumbs'] = [ {'name': 'Home', 'url': reverse_lazy('dashboard')}, {'name': 'Link Activities to Events', 'is_active': True} ] all_events = models.Event.objects.filter( container=context['object'], ).all() context['events'] = { event.id: event for event in all_events } for form in context['activitygroup_inline'].forms: activitygroup_kcs = set(form.instance.key_characteristics.all()) potential_event_ids = set() for event in all_events: event_kcs = set(event.key_characteristics.all()) if event_kcs & activitygroup_kcs: potential_event_ids.add(event.id) form.fields['events'].choices = models.Event.objects.filter( id__in=list(potential_event_ids) ).order_by('id').values_list('id', 'name') return context def forms_valid(self, form, inlines): self.object = form.save() for formset in inlines: instances = formset.save(commit=False) for inst in instances: initial_events = [] # This is code I added to work with the solution that I am now trying new_events = [] for f in formset: initial_events.append(f.initial['events']) # This is code I added to work with the solution that I am now trying new_events.append(f.cleaned_data['events'].first()) flat_initial = [item for sublist in initial_events for item in sublist] # This is code I added to work with the solution that I am now trying try: event = next(event for event in new_events if event is not None) # This is what I was previously doing to find the relevant event but it only works if there is one column in the table. except StopIteration: raise ValidationError('There must be at least one Activity Group linked to an event.') activityevent = inst.activityevent_set.filter(activity_group_id=inst.id, event_id=event.id) if activityevent.exists(): activityevent.delete() else: new_activityevent = models.ActivityEvent.objects.create( activity_group=inst, event=event, ) new_activityevent.save() inst.save() return HttpResponseRedirect(self.get_success_url()) 的{​​{1}}中进行了一项活动，如下图所示：

此外，用户可以通过单击添加其他按钮添加任意数量的项目。如果用户转到另一活动，然后再次转到该活动，则listview必须以用户保存它的方式出现。我使用共享首选项来保存已选中和未选中的首选项。但是该列表可能会变得很长，因此使用其他任何方法会更好吗？

Answer 1

您正在使用ListView。
这意味着您已经有了某种ArrayList来存储标签：如我所见，它是FirstItem，SecondItem，...和Description。
在此ListView的适配器中，创建一个名为isChecked的布尔字段，并在其中存储每个复选框的状态。
因此适配器将保留3个字段，而不是2个字段。

Answer 2

如果列表可能很长，并且每次打开时都需要重新创建它，则最好将此数据存储在某些本地数据库中，例如room persistence library。 SharedPreferences设计用于存储少量数据，例如您的案例中有关某一特定项目的信息。