一、创建ModelForm
from django.forms import ModelFormfrom appxx import modelsfrom django.forms import widgets as wdt # 因为重名，所以起个别名#定义一个类，比如BookForm，这个类要继承ModelForm，在这个类中再写一个原类Meta（规定写法，注意首字母是大写的）#在这个原类中，有以下属性（部分）：class BookForm(ModelForm): class Meta: model = models.Book # 对应的Model中的类 fields = "__all__" # 字段，如果是__all__，就表示列出所有的字段，或者使用列表列出想要的字段 exclude = None # 排除的字段 # error_messages用法 error_messages = { "title": { "required": "书名不能为空"}, "price": { "required": "售价不能为空"}, } # widgets用法，比如把输入用户名的input框给为Textarea widgets = { "name": wdt.Textarea(attrs={ "class": "c1"}) # 还可以自定义属性 } #labels，自定义在前端显示的名字 labels= { "title": "书名", "price": "售价", } 然后在 url 对应的视图函数中实例化这个类，把这个对象传给前端：
def add_book(request): form = forms.BookForm() return render(request, "add_book.html", { "form": form}) 然后在前端像Form组件那样渲染页面，
二、添加数据
保存数据的时候，不用挨个取数据了，只需要 save 一下即可。
from django.shortcuts import render,redirectfrom appxx import modelsfrom appxx import formsdef add_book(request): if request.method == "POST": form = forms.BookForm(request.POST) if form.is_valid(): form.save() return redirect("/book/") form = forms.BookForm() return render(request, "add_book.html", { "form": form}) 三、编辑数据
如果不使用 ModelForm，编辑的时候得显示之前的数据，还得挨个取一遍值；如果使用 ModelForm，只需要加一个instance=obj（obj是要修改的数据库的一条数据的对象）就可以得到同样的效果。
保存的时候要注意，一定要注意有这个对象（instance=obj），否则不知道更新哪一个数据。from django.shortcuts import render,redirectfrom appxx import modelsfrom appxx import formsdef edit_book(request, edit_book_id): edit_book= models.Book.objects.filter(id=edit_book_id).first() if request.method == "POST": form = forms.BookForm(request.POST, instance=edit_book) if form.is_valid(): form.save() return redirect("/book/") form = forms.BookForm(instance=edit_book) return render(request, "edit_book.html", { "form": form}) 总结： 从上边可以看到 ModelForm 用起来是非常方便的，比如增加修改之类的操作。但是也带来额外不好的地方，model和form之间耦合了。如果不耦合的话，form.save()方法也无法直接提交保存。 但是耦合的话使用场景通常局限用于小程序，写大程序就最好不用了。
四、完整示例代码
项目结构
urls.py
from django.conf.urls import urlfrom django.contrib import adminfrom appxx import viewsurlpatterns = [ url(r'^admin/', admin.site.urls), url(r"^book/$", views.book), url(r"^book/add/", views.add_book), url(r"^book/edit/(\d+)/", views.edit_book),]
views.py
from django.shortcuts import render,redirectfrom appxx import modelsfrom appxx import formsdef book(request): book_list = models.Book.objects.all() return render(request, "book.html", { "book_list": book_list})def add_book(request): if request.method == "POST": form = forms.BookForm(request.POST) if form.is_valid(): form.save() return redirect("/book/") form = forms.BookForm() return render(request, "add_book.html", { "form": form})def edit_book(request, edit_book_id): edit_book= models.Book.objects.filter(id=edit_book_id).first() if request.method == "POST": form = forms.BookForm(request.POST, instance=edit_book) if form.is_valid(): form.save() return redirect("/book/") form = forms.BookForm(instance=edit_book) return render(request, "edit_book.html", { "form": form}) models.py
from django.db import modelsclass Book(models.Model): id = models.AutoField(primary_key=True) title = models.CharField(max_length=32) price = models.DecimalField(max_digits=5, decimal_places=2) publish_date = models.DateField() publisher = models.ForeignKey(to="Publisher") authors = models.ManyToManyField(to="Author") def __str__(self): return self.titleclass Publisher(models.Model): id = models.AutoField(primary_key=True) name = models.CharField(max_length=32) def __str__(self): return self.nameclass Author(models.Model): id = models.AutoField(primary_key=True) name = models.CharField(max_length=32) def __str__(self): return self.name
forms.py
from django.forms import ModelFormfrom appxx import modelsfrom django.forms import widgets as wdtclass BookForm(ModelForm): class Meta: model = models.Book fields = "__all__" labels = { "title": "书名", "price": "售价", "publish_date": "出版日期", "publisher": "出版社", "authors": "作者" } widgets = { "title": wdt.TextInput(attrs={ "class": "form-control"}), "price": wdt.TextInput(attrs={ "class": "form-control"}), "publish_date": wdt.TextInput(attrs={ "class": "form-control", "type": "date"}), "publisher": wdt.Select(attrs={ "class": "form-control"}), "authors": wdt.SelectMultiple(attrs={ "class": "form-control"}), } error_messages = { "title": { "required": "书名不能为空"}, "price": { "required": "售价不能为空"}, "publish_date": { "required": "出版日期不能为空"}, "publisher": { "required": "出版社不能为空"}, "authors": { "required": "作者不能为空"}, } book.html
展示书籍
add_book.html和edit_book.html（两个页面代码一样）
添加书籍 {# panel开始 #}{# panel结束 #}{# panel-body开始 #}添加书籍
{# form开始 #} {# form结束 #}{# panel-body结束 #}