重写UpdateVi中get_表单的问题

Question

我尝试了很多方法来重写UpdateView中的get_form方法，但都没有成功。我想我要做的就是这样

class SystemUpdateView(UpdateView)
    def get_form(self, form_class):

        form = super(SystemUpdateView, self).get_form(form_class)
        //here I do some modifications to the form
        ....
        ....
        //then return that modified form
        return form

但它什么也没做。。。。有人知道为什么吗？ 我只是不明白为什么这样不行

我对CreateView做了同样的修改，它神奇地工作了，但在UpdateView中没有。在

但它什么也不做，也不出错。 然而，CreateView中的工作原理完全相同。。。。在

好吧。下面是CreateView中的工作原理

^{pr2}$

现在在SystemUpdateView中

class SystemUpdateView(AutoEventLogMixin, SuccessMessageMixin, PermissionRequiredMixin, UpdateView):
"""CRUD update view for :class:`~.System` objects"""

form_class = SystemForm
model = System
permission_required = 'services.change_system'
success_message = "System '%(name)s' updated successfully."
template_name = 'systems/system_form.html'

# when system edited need to modify accountable_team_history

def form_valid(self, form):

    system = self.get_object()

    if form.instance.accountable_team is not None:
        if system.accountable_team == form.instance.accountable_team:
            pass
        else:
            try:
                old_team_history = system.accountable_team_history.get(end_date__isnull=True)

                old_team_history.end_date = datetime.datetime.now()

                old_team_history.save()
            except AccountableTeamHistory.DoesNotExist:
                pass

            new_history = AccountableTeamHistory(resource=system,
                                         accountable_team=form.instance.accountable_team,
                                         effective_date=datetime.datetime.now())

            system.accountable_team_history.add(new_history)

            system.save()

    return super(SystemUpdateView, self).form_valid(form)

def get_form(self, form_class):

    form = super(SystemUpdateView, self).get_form(form_class)
    form.fields['primary_purpose_business_use'].label= "Primary purpose/business use"
    form.fields['secondary_purpose_business_uses'].label= "Secondary purpose/business uses"
    form.fields['primary_purpose_business_use'].choices = list()
    form.fields['secondary_purpose_business_uses'].choices = list()

    for optgroup in BusinessSystemType.objects.filter(parent__isnull=True):
        form.fields['primary_purpose_business_use'].choices.append(
            (optgroup.name,
             list((subtype.id, subtype.name) for subtype in BusinessSystemType.objects.filter(parent=optgroup))))

        form.fields['secondary_purpose_business_uses'].choices.append(
            (optgroup.name,
             list((subtype.id, subtype.name) for subtype in BusinessSystemType.objects.filter(parent=optgroup))))

    return form

此视图对窗体没有任何影响。在