**模型类**

```python
class Book(models.Model):
    name = models.CharField(max_length=32)
    price = models.IntegerField()
```

**路由**

```python
path('books/', views.BookView.as_view()),
path('books/<int:pk>', views.BookDetailView.as_view()),
```

**视图类**

```python
from django.views import View
from .models import Book
from django.http import JsonResponse
import json


class BookView(View):
    def get(self, request):
        # 获取所有图书
        book_list = Book.objects.all()

        # Object of type QuerySet is not JSON serializable  Queryset对象不允许用json序列化
        # json能序列化什么数据类型？
        '''
         +---------------+-------------------+
        | JSON          | Python            |
        +===============+===================+
        | object        | dict              |
        +---------------+-------------------+
        | array         | list              |
        +---------------+-------------------+
        | string        | str               |
        +---------------+-------------------+
        | number (int)  | int               |
        +---------------+-------------------+
        | number (real) | float             |
        +---------------+-------------------+
        | true          | True              |
        +---------------+-------------------+
        | false         | False             |
        +---------------+-------------------+
        | null          | None              |
        +---------------+-------------------+
        '''
        # 把qs [对象1，对象2]  对象转成  [{}，{}]
        l = []
        for book in book_list:
            l.append({'name': book.name, 'price': book.price})
        return JsonResponse({'code': 100, 'msg': '查询成功', 'results': l})

    def post(self, request):
        # 前端编码格式：urlencoded，json（规定）
        data = json.loads(request.body)  # 反序列化   # request.body bytes格式，json格式的 不是字符串
        # 在 Book表中插入一条记录
        book = Book.objects.create(**data)
        return JsonResponse({'code': 100, 'msg': '新增成功', 'results': {'name': book.name, 'price': book.price}})


修改一条  查询一条   删除一条 路由跟上面不一样，单独再写在一个视图类中

class BookDetailView(View):
    def get(self, request, pk):
        pass

    def delete(self, request, pk):
        pass

    def put(self, request, pk):
        pass
```

**路由**

```python
from rest_framework.routers import SimpleRouter
router = SimpleRouter()
router.register('books', views.BookView, 'books')
urlpatterns = [
]
urlpatterns += router.urls
```



**视图类**

```python
from .models import Book
from .serializer import BookSerializer
from rest_framework.viewsets import ModelViewSet
class BookView(ModelViewSet):
    queryset = Book.objects.all()
    serializer_class = BookSerializer
```



**序列化类**

```python
from rest_framework import serializers
from .models import Book
class BookSerializer(serializers.ModelSerializer):
    class Meta:
        model = Book
        fields = '__all__'
```

#1 请求来了---》执行 ---》views.BookView.as_view()(request)--->执行View类中as_view类方法中得 闭包函数 view
@classonlymethod
def as_view(cls, **initkwargs):
     def view(request, *args, **kwargs):
        self = cls(**initkwargs) # BookView类实例化得到对象
        self.dispatch(request, *args, **kwargs) # BookView类的dispatch
        
# 2 BookView类的dispatch没有---》View的dispatch
    # 根据请求方式，通过反射去视图类中【BookView】反射出跟请求方式同名的方法，执行
    def dispatch(self, request, *args, **kwargs):
        if request.method.lower() in self.http_method_names:
            handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
        else:
            handler = self.http_method_not_allowed
        return handler(request, *args, **kwargs)
    
    
    
# 3 以什么请求方式访问---》就会执行视图类中 跟请求方式同名的方法
    比如：http://127.0.0.1:8000/books/  get请求
    执行BookView类中get方法

path('books/', views.BookView.as_view()),
# 1 请求来了---》会执行views.BookView.as_view()(request) ---》找as_view---》BookView找不到---》APIView中找---》as_view--->就干了一个事--》去除了csrf认证
    @classmethod
    def as_view(cls, **initkwargs):
        view = super().as_view(**initkwargs) # 调用父类---》django原生View的as_view
        view=csrf_exempt(view) 
        # 等同于
        '''
        @csrf_exempt
        def view:
            pass
        '''
    
        return view             # 当前请求，去除掉了csrf认证
    
    
# 2 views.BookView.as_view()(request) 本质是执行  csrf_exempt(view)(request)
    -执行View的 中as_view内的view函数--》去除了csrf认证
# 3 本质在执行：self.dispatch(request, *args, **kwargs)
    BookView的dispatch---》BookView没有---》APIView找---》找到了
    def dispatch(self, request, *args, **kwargs):
        # 包装新的request
        request = self.initialize_request(request, *args, **kwargs)
        try:
            # 执行三大认证
            self.initial(request, *args, **kwargs)
            # 执行跟请求方式同名的视图类中得方法
            if request.method.lower() in self.http_method_names:
                handler = getattr(self, request.method.lower(),
                                  self.http_method_not_allowed)
            else:
                handler = self.http_method_not_allowed
            response = handler(request, *args, **kwargs)
            
            
        except Exception as exc:
            # 处理了全局异常
            response = self.handle_exception(exc)
        self.response = self.finalize_response(request, response, *args, **kwargs)
        return self.response
    
    
    
    
# 总结：
    1 APIView执行流程---》去除csrf--》执行了APIView的dispatch
    2 执行的as_view是APIView的as_view
    3 执行的dispatch也是APIView的dispatch