react经验5:访问子组件内容

应用场景

父级需要调用子组件的某函数

实现步骤

案例：创建自定义按钮
button.tsx

import { Ref, forwardRef, useImperativeHandle,ReactNode} from "react"
declare type ButtonProps = {
    /**按钮文字 */
    children?: ReactNode,
    onClick?: () => void
}
/**组件对外提供的可访问内容*/
export declare type ButtonInstance = {
	/**触发按钮点击事件*/
    forceClick: () => void;
}
/**自定义按钮组件 */
const Button = forwardRef((props: ButtonProps, ref: React.Ref<ButtonInstance | undefined>) => {
   function handleClick() {
   		alert('子组件的事件被触发')
        if (props.onClick) {
            props.onClick();
        }
    }
//声明可以被访问的内容
    useImperativeHandle(ref, () => {
        return {
           forceClick:handleClick
        }
    });

    return (
            <button  onClick={handleClick}>{props.children}</button>
    );
});
export default Button;

父组件中调用子组件的函数
parent.tsx

import Button from './button.tsx'
import {useState} from 'react'
const Parent=()=>{
	const [buttonInstance,setButtonInstance]=useState<ButtonInstance|null>()
	
	function handleParentClick(){
		buttonInstance?.forceClick()
	}

	return (
		<>
			<button onClick={handleParentClick}>父组件的原生按钮</button>
			<Button ref={setButtonInstance}>自定义的按钮组件</Button>
		</>
	)
}
export default Parent