在Django REST Framework中，GenericAPIView与多个Mixin类组合使用可以创建出功能丰富的视图。Mixin类提供了特定的行为，例如列表展示、创建、更新、删除等，而GenericAPIView则提供了处理HTTP请求的基础结构。以下是五个常用的Mixin类，它们可以与GenericAPIView结合
使用：
- ListModelMixin - 提供了
list()方法，用于展示模型的实例列表。 - CreateModelMixin - 提供了
create()方法，用于创建新的模型实例。 - RetrieveModelMixin - 提供了
retrieve()方法，用于展示单个模型实例的详细信息。 - UpdateModelMixin - 提供了
update()方法，用于更新现有的模型实例。 - DestroyModelMixin - 提供了
destroy()方法，用于删除模型实例。
这五个扩展类需要搭配GenericAPIView通用视图基类，因为五个扩展类的实现需要调用GenericAPIView提供的序列化器与数据库查询的方法。提供了几种后端视图（对数据资源进行增删改查）处理流程的实现，如果需要编写的视图属于这五种，则视图可以通过继承相应的扩展类来复用代码，减少自己编写的代码量。
1.ListModelMixin
列表视图扩展类，提供list(request, *args, **kwargs)方法快速实现列表视图，返回200状态码。
该Mixin的list方法会对数据进行过滤和分页。
class ListModelMixin:
"""
List a queryset.
"""
def list(self, request, *args, **kwargs):
queryset = self.filter_queryset(self.get_queryset())
page = self.paginate_queryset(queryset)
if page is not None:
serializer = self.get_serializer(page, many=True)
return self.get_paginated_response(serializer.data)
serializer = self.get_serializer(queryset, many=True)
return Response(serializer.data)基于扩展类实现BookView：
from rest_framework import status
from rest_framework.generics import GenericAPIView
from rest_framework.response import Response
from sers.models import Book
from .sers import BookSerializer
from rest_framework.mixins import ListModelMixin
class BookView(GenericAPIView,ListModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request):
return self.list(request)2.CreateModelMixin
创建视图扩展类，提供create(request, *args, **kwargs)方法快速实现创建资源的视图，成功返回201状态码。
如果序列化器对前端发送的数据验证失败，返回400错误。
class CreateModelMixin:
"""
Create a model instance.
"""
def create(self, request, *args, **kwargs):
serializer = self.get_serializer(data=request.data)
serializer.is_valid(raise_exception=True)
self.perform_create(serializer)
headers = self.get_success_headers(serializer.data)
return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
def perform_create(self, serializer):
serializer.save()
def get_success_headers(self, data):
try:
return {'Location': str(data[api_settings.URL_FIELD_NAME])}
except (TypeError, KeyError):
return {}基于扩展类实现BookView：
class BookView(GenericAPIView, ListModelMixin, CreateModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request):
return self.list(request)
def post(self, request):
return self.create(request)3.RetrieveModelMixin
详情视图扩展类，提供retrieve(request, *args, **kwargs)方法，可以快速实现返回一个存在的数据对象。
如果存在，返回200， 否则返回404。
class RetrieveModelMixin:
"""
Retrieve a model instance.
"""
def retrieve(self, request, *args, **kwargs):
instance = self.get_object()
serializer = self.get_serializer(instance)
return Response(serializer.data)基于扩展类实现BookDetailView：
class BookDetailView(GenericAPIView,RetrieveModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request, pk):
return self.retrieve(request, pk)4.UpdateModelMixin
更新视图扩展类，提供update(request, *args, **kwargs)方法，可以快速实现更新一个存在的数据对象。
同时也提供partial_update(request, *args, **kwargs)方法，可以实现局部更新。
成功返回200，序列化器校验数据失败时，返回400错误。
class UpdateModelMixin:
"""
Update a model instance.
"""
def update(self, request, *args, **kwargs):
partial = kwargs.pop('partial', False)
instance = self.get_object()
serializer = self.get_serializer(instance, data=request.data, partial=partial)
serializer.is_valid(raise_exception=True)
self.perform_update(serializer)
if getattr(instance, '_prefetched_objects_cache', None):
# If 'prefetch_related' has been applied to a queryset, we need to
# forcibly invalidate the prefetch cache on the instance.
instance._prefetched_objects_cache = {}
return Response(serializer.data)
def perform_update(self, serializer):
serializer.save()
def partial_update(self, request, *args, **kwargs):
kwargs['partial'] = True
return self.update(request, *args, **kwargs)
5.基于扩展类实现BookDetailView：
class BookDetailView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request, pk):
return self.retrieve(request, pk)
def put(self, request, pk):
return self.update(request, pk)
5.DestroyModelMixin
删除视图扩展类，提供destroy(request, *args, **kwargs)方法，可以快速实现删除一个存在的数据对象。
成功返回204，不存在返回404。
class DestroyModelMixin:
"""
Destroy a model instance.
"""
def destroy(self, request, *args, **kwargs):
instance = self.get_object()
self.perform_destroy(instance)
return Response(status=status.HTTP_204_NO_CONTENT)
def perform_destroy(self, instance):
instance.delete()基于扩展类实现BookDetailView：
class BookDetailView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request, pk):
return self.retrieve(request, pk)
def put(self, request, pk):
return self.update(request, pk)
def delete(self, request, pk):
return self.destroy(request, pk)整体代码，使用GenericAPIView结合视图扩展类，实现5个基本api接口，视图代码：
# Create your views here.
"""
基于GenericAPIView结合5个视图扩展类完成基本的5个API接口
ListModelMixin 提供了list方法，获取多条数据
CreateModelMixin 提供了create方法，添加一条数据
RetrieveModelMixin 提供了retrieve方法，获取一条数据
UpdateModelMixin 提供了update方法，更新一条数据
DestroyModelMixin 提供了destroy方法，删除一条数据
"""
# 设计增删改查查接口
# 序列化器
from rest_framework import serializers
from rest_framework.response import Response
from .models import Book
from rest_framework.generics import GenericAPIView
from rest_framework import status
from rest_framework.mixins import ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, \
DestroyModelMixin
class BookSerializer(serializers.ModelSerializer):
"""图书数据序列化器"""
class Meta:
model = Book
fields = '__all__'
class BookView(GenericAPIView, ListModelMixin, CreateModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request):
return self.list(request)
def post(self, request):
return self.create(request)
class BookDetailView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request, pk):
return self.retrieve(request, pk)
def put(self, request, pk):
return self.update(request, pk)
def delete(self, request, pk):
return self.destroy(request, pk)
路由不变：
urlpatterns = [
path('books/', BookView.as_view()),
re_path('books/(?P<pk>\d+)/', BookDetailView.as_view()),
]
