解决React Warning: Function components cannot be given refs. Attempts to access this ref will fail. Di

问题

当我使用如下方式调用组件子组件UploadModal并且绑定Ref时React报错“Warning: Function components cannot be given refs. Attempts to access this ref will fail. Did you mean to use React.forwardRef()?”；

const UploadModalRef = useRef(null);
const openUploadModal = () => {
 UploadModalRef.current.open();
}
// ...
<UploadModal ref={UploadModalRef} />

然而当我按照报错提示使用forwardRef包裹子组件UploadModal后依然报错“TypeError: Cannot read properties of null (reading 'open')”无法访问子组件的方法。

解决：

通过useImperativeHandle暴露子组件方法

import { forwardRef, useState, useImperativeHandle } from "react";

export default forwardRef(function UploadModal(props, ref) {
    const [Visible, setVisible] = useState(false);
    
    const 
        open = () => setVisible(true),
    ;

    useImperativeHandle(ref, () => {
        return {
            open,
        }
    })

    return (
        //...
    )
})

useImperativeHandle 是 React 中的一个 Hook，它能让你自定义由 ref 暴露出来的句柄。https://zh-hans.react.dev/reference/react/useImperativeHandle