- [ ] I have searched the [issues](https://github.com/vueComponent/ant-design-vue/issues) of this repository and believe that this is not a duplicate. ### Version 2.0.0-rc.8 ### Environment "vue": "^3.0.5" ### Reproduction link [](https://codesandbox.io/s/vue-antd-template-forked-4kwuo?file=/src/main.tsx) ### Steps to reproduce 在使用SubMenu时,通过map方法生成的SubMenu 使用onTitleClick 事件获取到的key为undefined ### What is expected? 想知道是否是我写的代码的问题 ### What is actually happening? 这样点击是时候所有submenu是同时展开的 <!-- generated by issue-helper. DO NOT REMOVE -->