from django.utils.deprecation import MiddlewareMixinclass Mymiddle(MiddlewareMixin):    def process_response(self,request,response):        response["Access-Control-Allow-Origin"] = "*"        if request.method == "OPTIONS":            # 复杂请求会先发预检            response["Access-Control-Allow-Headers"] = "Content-Type"            response["Access-Control-Allow-Methods"] = "PUT,PATCH,DELETE"        return response

在settings中注册中间件