Question

我已经尝试了其他类似问题的帖子，但我处理的代码是由第三方制作的，我遇到了一些小问题。我根本无法使用我想要的初始值定义其中一个表单。怎么办？

models.py

class Livro(models.Model):
codigo = models.AutoField(primary_key=True)
nome = models.CharField("Nome", max_length=50, unique = True)
autor = models.CharField("Autor", max_length=50, unique = True)
edicao = models.CharField("Edição", max_length=30, unique = True)
disciplina = models.ForeignKey(Disciplina)
tipo = models.CharField("Tipo", max_length=20, choices = Choices.tipo)
ano = models.CharField("Ano", max_length=30, choices = Choices.ano)
situacao = models.CharField("Situação", max_length=30, choices = Choices.situacao, blank = True, null = True)
def __unicode__(self):
    return self.nome

views.py

def cadastrar_livro(request):
form = LivroForm(request.POST or None)
if form.is_valid():
    salvo = form.save(commit=False)
    salvo.situacao = "Ativado"
    salvo.save()
    return HttpResponseRedirect('/principal')
return render_to_response('cadastrar_livro.html', locals(),      context_instance = RequestContext(request))

和choices.py

class Choices(models.Model):
    tipo = (
        ('1', 'Seriado'),
        ('2', 'Único'),
    )

    ano = (
        ('1', '1º'),
        ('2', '2º'),
        ('3', '3º'),
        ('4', 'Único'),
     )

    situacao = (
        ('Ativado', 'Ativado'),
        ('Desativado', 'Desativado'),
    )

我只需要选择能够预先选择Ativado，但无法找到任何解决方案。需要帮助谢谢。

Answer 1

您是否尝试在situacao字段中设置default参数。

situacao = models.CharField("Situação", max_length=30, choices=Choices.situacao, default=Choices.situacao[0][1], blank=True, null=True)

Answer 2

您可以在表单的 .initial = 中动态设置 __init__：

class FormChooseRegulation(forms.Form):
    regulation = forms.ChoiceField(required=True, label=_('Regulation'))

    def __init__(self, *args, **kwargs):
        regulations = kwargs.pop('regulations', ())
        regulation_last = kwargs.pop('regulation_last', None)
        super().__init__(*args, **kwargs)
        self.fields['regulation'].choices = regulations
        if regulation_last:
            self.fields['regulation'].initial = regulation_last

在视图中调用：

def regulation_selection(request):
    regulations = list(Regulation.objects.values_list('id', 'label'))
    form_regulation = FormChooseRegulation(
                regulations=regulations,
                regulation_last=request.session.get('regulation_id')
            )

如何在Django上预先选择下拉列表？

2 个答案: