react-父组件调用子组件dom

父组件通过 props 把方法传递给子组件

class Parent extends React.Component {getRef(ref){this.node = ref}
    render(){
        return(<Children getRef = {this.getRef} />
        )
    }
}

子组件一旦创建就会执行 ref 的回调

function Children (props) {
    return(
        <>
            <input ref={props.getRef} />
        </>
    )
    
}