据我所知,我可以像这样为单个元素使用refs:

const { useRef, useState, useEffect } = React; const App = () => { const elRef = useRef(); const [elWidth, setElWidth] = useState(); useEffect(() => { setElWidth(elRef.current.offsetWidth); }, []); return ( <div> <div ref={elRef} style={{ width: "100px" }}> Width is: {elWidth} </div> </div> ); }; ReactDOM.render( <App />, document.getElementById("root") ); <script src="https://unpkg.com/react@16/umd/react.production.min.js"></script> <script src="https://unpkg.com/react-dom@16/umd/react-dom.production.min.js"></script> <div id="root"></div>

我如何实现这个元素数组?显然不是这样的:(我知道,即使我没有尝试:)

const { useRef, useState, useEffect } = React; const App = () => { const elRef = useRef(); const [elWidth, setElWidth] = useState(); useEffect(() => { setElWidth(elRef.current.offsetWidth); }, []); return ( <div> {[1, 2, 3].map(el => ( <div ref={elRef} style={{ width: `${el * 100}px` }}> Width is: {elWidth} </div> ))} </div> ); }; ReactDOM.render( <App />, document.getElementById("root") ); <script src="https://unpkg.com/react@16/umd/react.production.min.js"></script> <script src="https://unpkg.com/react-dom@16/umd/react-dom.production.min.js"></script> <div id="root"></div>

我见过这个,所以才会这样。但是,我仍然不知道如何在这个简单的案例中实现这个建议。


当前回答

import { createRef } from "react";

const MyComponent = () => {
  const arrayOfElements = Array.from({ length: 10 }).map((_, idx) => idx + 1);
  const refs = arrayOfElements.map(() => createRef(null));

  const onCLick = (index) => {
    ref[index]?.current?.click();
  };

  return (
    <div>
      <h1>Defaults Elements</h1>
      {arrayOfElements.map((element, index) => (
        <div key={index} ref={refs[index]}>
          Default Elemnt {element}
        </div>
      ))}

      <h2>Elements Handlers</h2>
      {arrayOfElements.map((_, index) => (
        <button key={index} onClick={() => onCLick(index)}>
          Element {index + 1} Handler
        </button>
      ))}
    </div>
  );
};

其他回答

最简单和最有效的方法是根本不使用useRef。只需使用一个回调ref,在每次渲染时创建一个新的ref数组。

function useArrayRef() {
  const refs = []
  return [refs, el => el && refs.push(el)]
}

Demo

<div id="root"></div> <script type="text/babel" defer> const { useEffect, useState } = React function useArrayRef() { const refs = [] return [refs, el => el && refs.push(el)] } const App = () => { const [elements, ref] = useArrayRef() const [third, setThird] = useState(false) useEffect(() => { console.log(elements) }, [third]) return ( <div> <div ref={ref}> <button ref={ref} onClick={() => setThird(!third)}>toggle third div</button> </div> <div ref={ref}>another div</div> { third && <div ref={ref}>third div</div>} </div> ); } ReactDOM.render(<App />, document.getElementById("root")); </script> <script src="https://unpkg.com/@babel/standalone@7/babel.min.js"></script> <script src="https://unpkg.com/react@17/umd/react.production.min.js"></script> <script src="https://unpkg.com/react-dom@17/umd/react-dom.production.min.js"></script>

假设您的数组包含非原语,您可以使用WeakMap作为Ref的值。

function MyComp(props) {
    const itemsRef = React.useRef(new WeakMap())

    // access an item's ref using itemsRef.get(someItem)

    render (
        <ul>
            {props.items.map(item => (
                <li ref={el => itemsRef.current.set(item, el)}>
                    {item.label}
                </li>
            )}
        </ul>
    )
}

我使用useRef钩子创建我想独立控制的数据面板。首先我初始化useRef来存储一个数组:

import React, { useRef } from "react";

const arr = [1, 2, 3];

const refs = useRef([])

在初始化数组时,我们观察到它实际上是这样的:

//refs = {current: []}

然后我们应用map函数来创建面板,使用我们将引用的div标签,将当前元素添加到我们的引用中。带有一个按钮的当前数组:

arr.map((item, index) => {
  <div key={index} ref={(element) => {refs.current[index] = element}}>
    {item}
    <a
      href="#"
      onClick={(e) => {
        e.preventDefault();
        onClick(index)
      }}
    >
      Review
    </a>
})

最后一个函数接收按下按钮的索引,我们可以控制我们想要显示的面板

const onClick = (index) => {
  console.log(index)
  console.log(refs.current[index])
}

最后,完整的代码是这样的

import React, { useRef } from "react";

const arr = [1, 2, 3];

const refs = useRef([])
//refs = {current: []}

const onClick = (index) => {
  console.log(index)
  console.log(refs.current[index])
}

const MyPage = () => {
   const content = arr.map((item, index) => {
     <div key={index} ref={(element) => {refs.current[index] = element}}>
       {item}
       <a
         href="#"
         onClick={(e) => {
           e.preventDefault();
           onClick(index)
         }}
       >
         Review
       </a>
   })
   return content
}

export default MyPage

这对我很管用!希望这些知识对你有用。

import React, { useRef } from "react";

export default function App() {
  const arr = [1, 2, 3];

  const refs = useRef([]);

  return (
    <div className="App">
      {arr.map((item, index) => {
        return (
          <div
            key={index}
            ref={(element) => {
              refs.current[index] = element;
            }}
          >
            {item}
          </div>
        );
      })}
    </div>
  );
}

学分:https://eliaslog.pw/how-to-add-multiple-refs-to-one-useref-hook/

import { createRef } from "react";

const MyComponent = () => {
  const arrayOfElements = Array.from({ length: 10 }).map((_, idx) => idx + 1);
  const refs = arrayOfElements.map(() => createRef(null));

  const onCLick = (index) => {
    ref[index]?.current?.click();
  };

  return (
    <div>
      <h1>Defaults Elements</h1>
      {arrayOfElements.map((element, index) => (
        <div key={index} ref={refs[index]}>
          Default Elemnt {element}
        </div>
      ))}

      <h2>Elements Handlers</h2>
      {arrayOfElements.map((_, index) => (
        <button key={index} onClick={() => onCLick(index)}>
          Element {index + 1} Handler
        </button>
      ))}
    </div>
  );
};