一、视图层
1、FBV与CBV
FBV:基于函数的视图 CBV:基于类的视图 #使用CBV时,路由层写法 urlpatterns = [ #分析源码这里也可写成 url(r'^mycls/', views.view),这种格式与FBV路由层中一致 url(r'^mycls/', views.MyCls.as_view()),] ''' FBV与CBV中路由层都是:路由对应视图函数内存地址 ''' # 使用CBV时,首先在views文件中导入View模块 from django.views import View #定义类,继承View class MyCls(View): def get(self,request): return render(request,'index.html') def post(self,request): return HttpResponse('post')
View中部分源码:
#View中部分源码 @classonlymethod #绑定给类的方法 def as_view(cls, **initkwargs): #cls是我们写的MyCls for key in initkwargs: if key in cls.http_method_names: raise TypeError("You tried to pass in the %s method name as a " "keyword argument to %s(). Don't do that." % (key, cls.__name__)) if not hasattr(cls, key): raise TypeError("%s() received an invalid keyword %r. as_view " "only accepts arguments that are already " "attributes of the class." % (cls.__name__, key)) def view(request, *args, **kwargs): #定义在as_view内部,是闭包函数 #cls表示引用了as_viewde1作用域,也就是我们写的MyCls类 self = cls(**initkwargs) #self相当于MyCls实例化的对象 if hasattr(self, 'get') and not hasattr(self, 'head'): self.head = self.get self.request = request self.args = args self.kwargs = kwargs #self是MyCls的对象,self中没有dispatch方法,MyCls中也没有,还要从View中找 return self.dispatch(request, *args, **kwargs) view.view_class = cls view.view_initkwargs = initkwargs update_wrapper(view, cls, updated=()) update_wrapper(view, cls.dispatch, assigned=()) return view #调用路由层中调用as_view,会拿到 view 的内存地址 def dispatch(self, request, *args, **kwargs): # request.method获取请求类型,判断是否在self.http_method_names中 if request.method.lower() in self.http_method_names: # 反射,self是MyCls的对象;获取MyCls中 get/post 方法, handler = getattr(self, request.method.lower(), self.http_method_not_allowed) else: handler = self.http_method_not_allowed return handler(request, *args, **kwargs)
2、JsonResponse
# 在开发过程中前、后端使用的语言类型是不同的,这里就需要使用Json数据交换的文本格式。 #路由层 urlpatterns = [url(r'^index/', views.index)] #视图层 from django.shortcuts import HttpResponse import json #手动序列化 def index(request): res = {'name':'Bob','password':123} return HttpResponse(json.dumps(res)) #前端结果{"name":"Bob","password",123} res = {'name':'Bob大帅比','password':123} return HttpResponse(json.dumps(res))#前端显示结果不能识别中文 #将dumps中ensure_ascli参数改为Flase,序列化时保证数据内容不变 return HttpResponse(json.dumps(res),ensure_ascii=False) # django自行序列化 from django.http import JsonResponse def index(request): res={'name':'Bob大帅比','password':123} return JsonResponse(res,json_dumps_params={'ensure_ascii':False})
二、简单的文件上传
前端需要注意的点: 1.method需要指定成post 2.enctype需要改为formdata格式 <form action="{% url app01_index %}" method="post" enctype="multipart/form-data"> <input type="file" name="my_file"> <input type="submit"> ######## 后端暂时需要注意的是: 1.配置文件中注释掉csrfmiddleware中间件 2.通过request.FILES获取用户上传的post文件数据 def upload_file(request): if request.method == 'POST': print('path:',request.path) print('full_path:',request.get_full_path()) # print(request.FILES) file_obj = request.FILES.get('my_file') print(file_obj.name) with open(file_obj.name,'wb') as f: for line in file_obj.chunks(): f.write(line) return HttpResponse('OK') return render(request,'index.html')