对于每辆车点击我需要在浏览器中显示车名

Question

• 每次点击汽车，我都需要在浏览器中显示汽车名称。

  • 我以为我会在react中使用类似于js的e.target.innerText
  • 但它不起作用。
  • 使用 map 我能够迭代数组。
  • 但不知道如何实现点击事件。
  • 我是否使用 useState correclty 来设置车名
  • 在下面提供我的代码 sn-p 和 sanbox。

  https://codesandbox.io/s/upbeat-ptolemy-su53h

  function App() {
    const [carbrand, setCarBrand] = useState();
    let cars = ["honda", "toyota", "bmw"];
    let eachCarName = cars.map(name => {
      console.log("name--->", name);
      let carDiv = <div>{name}</div>;
      return carDiv;

      //return name;
    });

    console.log("eachCarName--->", eachCarName);
    const eachCarClick = e => {
      console.log("eachCarClick--->", e);
      console.log("eachCarClick e.target.innerText--->", e.target.innerText);
    };

    // const setCarBrand = eachCarName;
    // const carbrand = eachCarName;

    return (
      <div className="App">
        <h1 onClick={eachCarClick(event)}>{eachCarName}</h1>
      </div>

Answer 1

我觉得你的 onClick 有问题，这里是我的示例代码

代码沙盒：https://codesandbox.io/s/elated-field-3wj2x

代码：

import React, { useState } from "react";
import ReactDOM from "react-dom";

import "./styles.css";

function App() {
  const [carbrand, setCarBrand] = useState();
  let cars = ["honda", "toyota", "bmw"];
  let eachCarName = cars.map((name, index) => {
    return (
      <h1 onClick={e => eachCarClick(e)} key={index}>
        {name}
      </h1>
    );
  });

  const eachCarClick = e => {
    setCarBrand(e.target.innerText);
  };

  // const setCarBrand = eachCarName;
  console.log(carbrand);

  return (
    <div className="App">
      <div>{eachCarName}</div>
    </div>
  );
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

Answer 2

这里的代码将为你完成这项工作

import React, { useState } from "react";
import ReactDOM from "react-dom";

import "./styles.css";

function App() {
  const [carbrand, setCarBrand] = useState();
  let cars = ["honda", "toyota", "bmw"];
  let eachCarName = cars.map(name => {
    console.log("name--->", name);
    let carDiv = <div>{name}</div>;
    return carDiv;

    //return name;
  });

  console.log("eachCarName--->", eachCarName);
  const eachCarClick = e => {
    console.log("eachCarClick--->", e);
    console.log("eachCarClick e.target.innerText--->", e.target.innerText);
  };

  // const setCarBrand = eachCarName;
  // const carbrand = eachCarName;

  return (
    <div className="App">
      <h1 onClick={eachCarClick}>{eachCarName}</h1>
    </div>
  );
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

这是一个代码框，可以满足您的需求https://codesandbox.io/s/polished-cloud-fwj6h

Answer 3

这里有一些问题，但功能上最大的问题是没有 innerText 属性 - e.target 将返回 HTML 元素，您需要获取 value 或 id 或任何您需要的属性其中。在下面的示例中，我将其称为 ID

代码沙盒：https://codesandbox.io/embed/spring-mountain-1v8873222-wpl0d

代码：

function App() {
  const [carbrand, setCarBrand] = useState('');
  let cars = ["honda", "toyota", "bmw"];

  return (
    <div className="App">
      {cars.map(carName => <h1 id={carName} onClick={e => setCarBrand(e.target.id)}>{carName}</h1>)}
      {carbrand && <p>you clicked: {carbrand}</p>}
    </div>
  );
}```

I opted for doing the mapping inline for simplicity.  There's no real issue either way but stylistically, for something so simple this would be my preference.