如何在Django中使用forms.ModelForm创建下拉框？

Question

我正在尝试在我的表单中添加一个下拉框。我尝试的是：

from django import forms
from .models import Car

class CarForm(forms.ModelForm):
    owner_name = forms.CharField(max_length=100, label='Owner Name', required=True)
    car_type = forms.ChoiceField(choices=Car.CarTypes.choices, label='Car Type', required=True)

    class Meta:
        model = Car
        fields = ('owner_name', 'car_type')

它将car_type字段添加到表单中，但出于某种原因，它不是下拉列表（这是一个可以填充的常规空框）。{}看起来像：

    class CarTypes(models.TextChoices):
        X = 'some_x'
        Y = 'somy_y'
        # ...

原因可能是什么

在我的Car类中，我有：car_type = models.CharField(max_length=24, choices=CarTypes.choices, default=CarTypes.X)。可能是吗？我想CharField会让它变成空盒子。但是将其更改为ChoiceField以：module 'django.db.models' has no attribute 'ChoiceField'结尾。如何解决

我尝试了这个approach，但它使用元组而不是类。从这里的示例中，我看到它们使用两个值元组的元组，如(('a','A'),('b','B'))，我使用的是类。这可能是原因吗

在我的html中，我有：

    <form method="post" class="form-group">
      {% csrf_token %}
      {% for field in form %}
        <div class="form-group col-md-12 mb-3">
          <label for="{{ field.label }}">{{ field.label }}</label>
          <input type="text" class="form-control" id="{{ field.label }}" name="{{ field.name }}">
        </div>
      {% endfor %}
      <hr class="mb-4">
      <button type="submit" class="btn btn-secondary btn-lg btn-block">Submit New Car</button>
    </form>

这辆车看起来像：

class Car(models.Model):

    class CarTypes(models.TextChoices):
        X = 'some_x'
        Y = 'somy_y'
        # ...

    owner_name = models.CharField(max_length=100,unique=True)
    car_type = models.CharField(max_length=24, choices=CarTypes.choices, default=CarTypes.X)

    def __str__(self):
        return self.owner_name

Answer 1

您不需要覆盖模型字段。见Field types-Django Docs

If the model field has choices set, then the form field’s widget will be set to Select, with choices coming from the model field’s choices.

以下代码应该执行您想要的操作：

forms.py

from django import forms
from .models import Car

class CarForm(forms.ModelForm):
    class Meta: 
        model = Car 
        fields = ['owner_name', 'car_type']

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['owner_name'].widget.attrs.update({"class": "form-control"})
        # or iterate over field to add class for each field
        for field in self.fields:
            self.fields[field].widget.attrs.update({'class':"form-control"})

您可以在__init__方法中添加任何html属性

html:

<form method="post" class="form-group">
  {% csrf_token %}
    <div class="form-group col-md-12 mb-3">
      <label for="{{ form.owner_name.label }}">{{ form.owner_name.label }}</label>
      {{ form.owner_name }}
    </div>

    <div class="form-group col-md-12 mb-3">
        <label for="{{ form.car_type.label }}">{{ form.car_type.label }}</label>
        {{ form.car_type }}
    </div>
  <hr class="mb-4">
  <button type="submit" class="btn btn-secondary btn-lg btn-block">Submit New Car</button>
</form>

或者您可以使用^{}-Django Docs将它们包装在<p>标记中

更新

---

手动渲染窗体：

<form method="post" class="form-group">
    {% csrf_token %}
    <div class="form-group col-md-12 mb-3">
        <label for="{{ form.owner_name.label }}">{{ form.owner_name.label }}</label>
        <input type="text" class="form-control" id="{{ form.owner_name.auto_id }}" name="{{ form.owner_name.name }}">
    </div>

    <div class="form-group col-md-12 mb-3">
        <label for="{{ form.car_type.label }}">{{ form.car_type.label }}</label>
        <select id="{{ form.car_type.auto_id }}" name="{{ form.car_type.name }}">
        {% for value, label in form.fields.car_type.choices %}
            <option value="{{ value }}"{% if form.car_type.value == value %} selected{% endif %}>{{ label }}</option>
        {% endfor %}
        </select>
    </div>
  <hr class="mb-4">
  <button type="submit" class="btn btn-secondary btn-lg btn-block">Submit New Car</button>
</form>

Answer 2

尝试使用以下方法Choices：-

models.py

choices = [
    ('choice1', 'choice1'),
    ('choice2',"choice2"),
    ('choice3',"choice3")
]

class Car(models.Model):

    owner_name = models.CharField(max_length=100,unique=True)
    car_type = models.CharField(max_length=24, choices=choices, default='choice1')

    def __str__(self):
        return self.owner_name

然后别忘了做migrations

请参阅此->https://docs.djangoproject.com/en/3.0/ref/models/fields/#django.db.models.Field.choices

Answer 3

对于Django3.1，可以通过widgets实现这一点。以下是您可以完成此任务的方法：

from django.forms import ModelForm, Select, TextInput
from .models import Car

class CarForm(ModelForm):
    class Meta:
        model = Car
        fields = ('owner_name', 'car_type')
        widgets = {
            'owner_name': TextInput(),
            'car_type': Select(),
        }

模型应该是这样的：

    class Car(models.Model):
        choices = [('X':'some_x'), ('Y': 'some_y']
        owner_name = models.CharField(max_length=100,unique=True)
        car_type = models.CharField(max_length=24, choices=choices, default='some_y')

        def __str__(self):
            return self.owner_name```