protected virtual void OnWriting(SerializationWritingEventArgs args)
        {
            var e = this.Writing;

            if (e != null)
            {
                e(this, args);
            }
        }
        private bool OnWriting(SerializationWriterContext context)
        {
            //创建事件参数对象
            var args = new SerializationWritingEventArgs(context);

            //激发“Writing”事件
            this.OnWriting(args);

            return(args.Cancel);
        }