我正在尝试带有反应16.7的钩子的功能组件,有一个错误：
SRC /组件/页脚/ index.js
function Footer() {
const [selectedTab,setSelectedTab] = useState('redTab');
const [hidden,setHidden] = useState(false);
const [fullScreen,setFullScreen] = useState(false);
//...
}
的package.json
我该怎么办？
确保将react-dom升级到16.7.0-alpha.0.
的package.json
{
"dependencies": {
"react": "16.7.0-alpha.0","react-dom" "16.7.0-alpha.0",...
},...
}
也许你只是在没有安装新版本的情况下碰撞了package.json中的版本. You can remove node_modules and install again.
npm ci
例
const { useState } = React;
function Footer() {
const [selectedTab,setFullScreen] = useState(false);
return (
<div>
<button onClick={() => setSelectedTab('blueTab')}>{selectedTab}</button>
<button onClick={() => setHidden(isHidden => !isHidden)}>
{hidden ? 'hidden' : 'visible'}
</button>
<button onClick={() => setFullScreen(isFullScreen => !isFullScreen)}>
{fullScreen ? 'fullscreen' : 'windowed'}
</button>
</div>
);
}
ReactDOM.render(
<Footer />,document.getElementById('root')
);
<script src="https://unpkg.com/react@16.7.0-alpha.0/umd/react.development.js"></script> <script src="https://unpkg.com/react-dom@16.7.0-alpha.0/umd/react-dom.development.js"></script> <div id="root"></div>
