更新React以使用Hooks

Question

我已经将 react 和 react-dom 更新到版本16.8.6，但是仍然出现此错误：

TypeError: Object(...) is not a function

在此代码行中显示：

const [count, setCount] = useState(0);

完整代码：

import React, { useState } from 'react';

export default () => {
  const [count, setCount] = useState(0);
  return <button onClick={() => setCount(count + 1)}>Clicked {count} times</button>;
};

如何确保我已将react和react-dom更新到最新版本？我从package.json中删除了软件包，并使用此命令再次安装它们：

npm install --save react react-dom

然后我看到 react 和 react-dom 被添加到具有最新版本的package.json中。

如果react和react-dom正确更新，如何使Hooks工作？

我的package.json文件的一部分：

"dependencies": {
"@material-ui/core": "3.9.2",
"@material-ui/icons": "^3.0.2",
"babel-polyfill": "6.26.0",
"immutable": "3.8.2",
"moment": "2.21.0",
"prop-types": "15.6.1",
"react": "^16.8.6",
"react-dom": "^16.8.6",
"react-grid-layout": "0.16.2",
"react-helmet": "5.2.0",
"react-jss": "8.6.1",
"react-loadable": "5.4.0",
"react-modal": "3.3.2",
"react-number-format": "3.5.0",
"react-redux": "5.0.7",
"react-router-dom": "5.0.0",
"react-router-redux": "5.0.0-alpha.9",
"recompose": "0.30.0",
"redux": "4.0.0",
"redux-immutable": "4.0.0",
"redux-saga": "1.0.2",
"reselect": "3.0.1",
"styled-components": "3.3.2",
...
}