code: def init_app(self, app):
          
          if app.config.GRIDFS_SETTINGS and isinstance(app.config.GRIDFS_SETTINGS, dict):
              self.GRIDFS_SETTINGS = app.config.GRIDFS_SETTINGS
              self.app = app
  
          else:
              raise ValueError(
                  "nonstandard sanic config GRIDFS_URIS,GRIDFS_URIS must be a Dict[Bucket_name,Tuple[dburl,collection]]")
  
          @app.listener("before_server_start")
          async def init_mongo_connection(app, loop):
              for bucket_name, (dburl,collection) in app.config.GRIDFS_SETTINGS.items():
                  if isinstance(dburl,str):
                      bucket = GridFSBucket(dburl,ioloop=loop,collection = collection).bucket
                  else:
                      bucket = GridFSBucket(ioloop=loop,collection = collection,**dburl).bucket
                  self.GridFSs[bucket_name] = bucket
  
          @app.listener("before_server_stop")
          async def sub_close(app, loop):
              log.info("mongo connection {numbr}".format(numbr=len(self.GridFSs)))
              for bucket_name,bucket in self.GridFSs.items():
                  bucket.client.close
                  log.info("{bucket_name} connection closed".format(bucket_name=bucket_name))
  
  
          if "extensions" not in app.__dir__():
              app.extensions = {}
          app.extensions['SanicGridFS'] = self
  
          app.GridFS = self.GridFSs
          return self
docs: 绑定app