---
title: "使用基于类的视图处理表单"
version: 2.2
locale: zh-hans
source: https://docs.djangoproject.com/zh-hans/2.2/topics/class-based-views/generic-editing/
canonical: https://djangodocs.dev/zh-hans/2.2/topics/class-based-views/generic-editing/
---
# 使用基于类的视图处理表单

表单处理通常有3个途径：

- 初始 GET （空白或预填充表单）
- 带有合法数据的POST（通常是带有错误的重新显示的表单）
- 带有合法数据的POST（处理数据和通常重定向）

自己实现这个会导致很多重复的样板代码（查看 [Using a form in a view](/zh-hans/2.2/topics/forms/#using-a-form-in-a-view) ）。为了避免这个问题，Django 提供了一组通用基于类的视图来处理表单。

## 基础表单

提供一个简单的联系表单：

*forms.py*

```python
from django import forms

class ContactForm(forms.Form):
    name = forms.CharField()
    message = forms.CharField(widget=forms.Textarea)

    def send_email(self):
        # send email using the self.cleaned_data dictionary
        pass
```

可以使用 `FormView` 构建视图：

*views.py*

```python
from myapp.forms import ContactForm
from django.views.generic.edit import FormView

class ContactView(FormView):
    template_name = 'contact.html'
    form_class = ContactForm
    success_url = '/thanks/'

    def form_valid(self, form):
        # This method is called when valid form data has been POSTed.
        # It should return an HttpResponse.
        form.send_email()
        return super().form_valid(form)
```

注意：

- FormView 继承了 [`TemplateResponseMixin`](/zh-hans/2.2/ref/class-based-views/mixins-simple/#django.views.generic.base.TemplateResponseMixin) ，因此可以在这里使用 [`template_name`](/zh-hans/2.2/ref/class-based-views/mixins-simple/#django.views.generic.base.TemplateResponseMixin.template_name) 。
- 默认实现了 [`form_valid()`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.FormMixin.form_valid)  简单重定向至 [`success_url`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.FormMixin.success_url) 。

## 模型表单

通用视图在模型一起工作时真的很赞。这些通用视图将自动创建 [`ModelForm`](/zh-hans/2.2/topics/forms/modelforms/#django.forms.ModelForm) ，只要他们能找出要使用的模型类：

- 如果已经给出了 [`model`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.ModelFormMixin.model) 属性，则使用这个模型类。
- 如果 [`get_object()`](/zh-hans/2.2/ref/class-based-views/mixins-single-object/#django.views.generic.detail.SingleObjectMixin.get_object) 返回一个对象，则使用这个对象的类。
- 如果已经给出了 [`queryset`](/zh-hans/2.2/ref/class-based-views/mixins-single-object/#django.views.generic.detail.SingleObjectMixin.queryset)  ，则使用这个查询集的模型。

模型表单视图提供一个 [`form_valid()`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.ModelFormMixin.form_valid) 实现，来自动保存模型。如果你有特别的需求，你可以覆盖它。下面是例子。

你甚至不需要为 [`CreateView`](/zh-hans/2.2/ref/class-based-views/generic-editing/#django.views.generic.edit.CreateView) 或 [`UpdateView`](/zh-hans/2.2/ref/class-based-views/generic-editing/#django.views.generic.edit.UpdateView) 提供 `success_url` 。如果可用，它们将在模型对象上使用 [`get_absolute_url()`](/zh-hans/2.2/ref/models/instances/#django.db.models.Model.get_absolute_url) 。

如果你想使用一个自定义的  [`ModelForm`](/zh-hans/2.2/topics/forms/modelforms/#django.forms.ModelForm) （比如添加额外的验证），用来在视图上简单设置 [`form_class`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.FormMixin.form_class) 。

> **Note**
>
> 当指定一个自定义表单类时，必须也要指定模型，即使 [`form_class`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.FormMixin.form_class) 可能是一个 [`ModelForm`](/zh-hans/2.2/topics/forms/modelforms/#django.forms.ModelForm) 。

首先我们需要添加 [`get_absolute_url()`](/zh-hans/2.2/ref/models/instances/#django.db.models.Model.get_absolute_url) 到 `Author` 类：

*models.py*

```python
from django.db import models
from django.urls import reverse

class Author(models.Model):
    name = models.CharField(max_length=200)

    def get_absolute_url(self):
        return reverse('author-detail', kwargs={'pk': self.pk})
```

然后可以使用 [`CreateView`](/zh-hans/2.2/ref/class-based-views/flattened-index/#CreateView) 并友好的执行实际工作。注意这里我们如何配置通用基于类的视图。我们不用自己编写任何逻辑：

*views.py*

```python
from django.urls import reverse_lazy
from django.views.generic.edit import CreateView, DeleteView, UpdateView
from myapp.models import Author

class AuthorCreate(CreateView):
    model = Author
    fields = ['name']

class AuthorUpdate(UpdateView):
    model = Author
    fields = ['name']

class AuthorDelete(DeleteView):
    model = Author
    success_url = reverse_lazy('author-list')
```

> **Note**
>
> 我们必须在这里使用 [`reverse_lazy()`](/zh-hans/2.2/ref/urlresolvers/#django.urls.reverse_lazy) ，而不是 `reverse()` ，因为在文件导入时不加载  urls 。

`fields` 属性的工作方式同 [`ModelForm`](/zh-hans/2.2/topics/forms/modelforms/#django.forms.ModelForm) 中内部 `Meta` 类的 `fields` 属性一样。除非你使用其他方式定义表单类，该属性是必需的，如果属性不存在，视图将引发 [`ImproperlyConfigured`](/zh-hans/2.2/ref/exceptions/#django.core.exceptions.ImproperlyConfigured) 异常。

如果同时指定了 [`fields`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.ModelFormMixin.fields) 和 [`form_class`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.FormMixin.form_class) 属性，将会引发 [`ImproperlyConfigured`](/zh-hans/2.2/ref/exceptions/#django.core.exceptions.ImproperlyConfigured) 异常。

最后将这些新视图挂钩到URLconf中：

*urls.py*

```python
from django.urls import path
from myapp.views import AuthorCreate, AuthorDelete, AuthorUpdate

urlpatterns = [
    # ...
    path('author/add/', AuthorCreate.as_view(), name='author-add'),
    path('author/<int:pk>/', AuthorUpdate.as_view(), name='author-update'),
    path('author/<int:pk>/delete/', AuthorDelete.as_view(), name='author-delete'),
]
```

> **Note**
>
> 这些视图继承 [`SingleObjectTemplateResponseMixin`](/zh-hans/2.2/ref/class-based-views/mixins-single-object/#django.views.generic.detail.SingleObjectTemplateResponseMixin) ，它使用 [`template_name_suffix`](/zh-hans/2.2/ref/class-based-views/mixins-single-object/#django.views.generic.detail.SingleObjectTemplateResponseMixin.template_name_suffix) 来构建基于模型的 [`template_name`](/zh-hans/2.2/ref/class-based-views/mixins-simple/#django.views.generic.base.TemplateResponseMixin.template_name) 。
>
> 在这个例子里：
>
> - [`CreateView`](/zh-hans/2.2/ref/class-based-views/flattened-index/#CreateView) 和 [`UpdateView`](/zh-hans/2.2/ref/class-based-views/flattened-index/#UpdateView) 使用 `myapp/author_form.html` 。
> - [`DeleteView`](/zh-hans/2.2/ref/class-based-views/flattened-index/#DeleteView) 使用 `myapp/author_confirm_delete.html` 。
>
> 如果你想为 [`CreateView`](/zh-hans/2.2/ref/class-based-views/flattened-index/#CreateView) 和 [`UpdateView`](/zh-hans/2.2/ref/class-based-views/flattened-index/#UpdateView) 制作单独的模板，你可以在视图类上设置 [`template_name`](/zh-hans/2.2/ref/class-based-views/mixins-simple/#django.views.generic.base.TemplateResponseMixin.template_name) 或 [`template_name_suffix`](/zh-hans/2.2/ref/class-based-views/mixins-single-object/#django.views.generic.detail.SingleObjectTemplateResponseMixin.template_name_suffix) 。

## 模型和 `request.user`

若要跟踪使用 [`CreateView`](/zh-hans/2.2/ref/class-based-views/flattened-index/#CreateView) 创建的用户，你可以使用自定义的 [`ModelForm`](/zh-hans/2.2/topics/forms/modelforms/#django.forms.ModelForm) 来执行此操作。首先，在模型里添加外键关系：

*models.py*

```python
from django.contrib.auth.models import User
from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=200)
    created_by = models.ForeignKey(User, on_delete=models.CASCADE)

    # ...
```

在这个视图中，确保你没有在要编辑的字段列表中包含 `created_by` 字段 ，并且要覆盖 [`form_valid()`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.ModelFormMixin.form_valid) 来添加用户：

*views.py*

```python
from django.contrib.auth.mixins import LoginRequiredMixin
from django.views.generic.edit import CreateView
from myapp.models import Author

class AuthorCreate(LoginRequiredMixin, CreateView):
    model = Author
    fields = ['name']

    def form_valid(self, form):
        form.instance.created_by = self.request.user
        return super().form_valid(form)
```

[`LoginRequiredMixin`](/zh-hans/2.2/topics/auth/default/#django.contrib.auth.mixins.LoginRequiredMixin) 防止那些未登录的用户访问表单。如果忽略，那么你将需要在 [`form_valid()`](/zh-hans/2.2/ref/class-based-views/mixins-editing/#django.views.generic.edit.ModelFormMixin.form_valid) 里处理未授权的用户。

## AJAX 案例

下面是一个展示了如何实现适用于 AJAX 请求的表单以及普通表单的 POST 请求：

```
from django.http import JsonResponse
from django.views.generic.edit import CreateView
from myapp.models import Author

class AjaxableResponseMixin:
    """
    Mixin to add AJAX support to a form.
    Must be used with an object-based FormView (e.g. CreateView)
    """
    def form_invalid(self, form):
        response = super().form_invalid(form)
        if self.request.is_ajax():
            return JsonResponse(form.errors, status=400)
        else:
            return response

    def form_valid(self, form):
        # We make sure to call the parent's form_valid() method because
        # it might do some processing (in the case of CreateView, it will
        # call form.save() for example).
        response = super().form_valid(form)
        if self.request.is_ajax():
            data = {
                'pk': self.object.pk,
            }
            return JsonResponse(data)
        else:
            return response

class AuthorCreate(AjaxableResponseMixin, CreateView):
    model = Author
    fields = ['name']
```