TypeError:instance.render不是函数(finishClassComponent)

Question

我是react.js的新手。我用"create-react-app"创建了一个项目。我正在关注文档。但我犯了这个错误。这是我的index.js:

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
class Square extends React.Component {
render() {
return (
<button className="square">
{this.props.value}
</button>
);
}
}
class Board extends React.Component {
renderSquare(i) {
return <Square value={i} />;
}
}
ReactDOM.render(
<React.StrictMode>
<Board/>
</React.StrictMode>,
document.getElementById('root')
);

Answer 1

您的Board组件缺少render()功能。

更改

class Board extends React.Component {
renderSquare(i) {
return <Square value={i} />;
}
}

至

class Board extends React.Component {
render() {
return <Square value={"someValue"} />;
}
}