django - MultipleChoiceField/CheckboxSelectMultiple 值未在绑定(bind)表单上恢复

Question

我正在构建表单的“编辑”页面。此页面应该显示包含已保存数据的表单，因此该表单已预先填充了已保存的数据。对于大多数字段来说，它工作得很好，但我遇到了无法恢复的 MultipleChoiceField/CheckboxSelectMultiple 值的问题。因此，不是用保存的表单中的数据选中相应的复选框，而是将它们全部取消选中。这是为什么？

表单.py

class MemberForm( forms.ModelForm ):

    # ......

    MODEL_CATEGORIES = (
        ('advisor', 'advisor'),
        ('member', 'member'),
        ('admin', 'admin'),
    )


    model_categories = forms.MultipleChoiceField(
            widget = forms.CheckboxSelectMultiple,
            choices = MODEL_CATEGORIES
    )

    class Meta:
        model = Member
        fields = [ 'model_categories' ]

型号

class Member( models.Model ):

    model_categories = models.CharField(
            max_length = 255,
            null = True,
            blank = True )

Controller

def profile_edit_form( request ):
    user = request.user or None

    # Get user member profile instance
    instance = get_object_or_404( Member, author = user )

    form = MemberForm( request.POST or None, instance = instance )

    context = {
        "form"    : form,
        "instance": instance
    }

    if form.is_valid():
        # ...
        return redirect( 'profile_display' )
    else:
        # Initial form display, and redisplay of invalid form
        return render( request, 'profile_edit_form_view.html', context )

模板

<form action="/accounts/profile-edit-form/" method="post">
    {% csrf_token %}

    {{ form }}


    <input type="submit" value="Submit"/>
</form>

Answer 1

您可以尝试使用initial形式

form = MemberForm( request.POST or None, instance = instance, 
                                         initial={'model_categories': 'advisor'})