use Ref in React(父组件和子组件交互)

通常情况下不要用Ref去获取child component： In React, it’s generally recommended to use props and state to manage your component data flow. 

While refs are a powerful tool, they should be used sparingly and only when necessary. Excessive use of refs can lead to code that is harder to understand and maintain. Always opt to use props and state for data flow in React components when possible.

see below:

https://blog.logrocket.com/use-forwardref-react/

https://blog.logrocket.com/complete-guide-react-refs/

https://refine.dev/blog/react-useref-hook-and-ref/#using-the-useref-hook-in-an-application

https://www.altcademy.com/blog/how-to-call-one-component-from-another-component-in-reactjs/  (利用Ref，从Parent组件调用子组件的方法)