reactjs - TS2339 : Property X does not exist on type '{}'

Question

我似乎无法解决这个错误。

ERROR in App.tsx(9,15) TS2339: Property 'count' does not exist on type '{}'.

App.tsx

import React from "react";

import Test from "./Test";

const App = () => {
  return (
    <div>
      <Test count={1} />
    </div>
  );
}

export default App;

测试.tsx

import React from "react";

interface Props{
  count: number
}
interface State{}

class Test extends React.Component<Props, State>{
  render(){
    return <div>{this.props.count}</div>;
  }
}

export default Test;

我的tsconfig如下，

{
  "compilerOptions": {
    "allowJs": true,
    "jsx": "react",
    "module": "es6",
    "target": "es5",
    "allowSyntheticDefaultImports": true
  },
  "include": ["src"]
}

我也在使用 webpack 来构建应用程序。我正在使用 ts-loader

加载 typescript

package.json

  "dependencies": {
    "axios": "^0.18.0",
    "express": "^4.16.3",
    "fetch": "^1.1.0",
    "less": "^3.8.0",
    "mathjax": "^2.7.5",
    "node-html-parser": "^1.1.8",
    "react": "^16.4.2",
    "react-dom": "^16.4.2",
    "webpack": "^4.16.3"
  },
  "devDependencies": {
    "@types/express": "^4.16.0",
    "classnames": "^2.2.6",
    "css-loader": "^1.0.0",
    "less-loader": "^4.1.0",
    "nodemon": "^1.18.3",
    "style-loader": "^0.21.0",
    "ts-loader": "^4.4.2",
    "ts-node": "^7.0.0",
    "typescript": "^3.0.1",
    "webpack-cli": "^3.1.0",
    "webpack-dev-server": "^3.1.5"
  }

谢谢!

Answer 1

安装 React 类型定义:

npm install -D @types/react @types/react-dom

如果没有安装类型，TS 无法正确推断 JSX 元素所需的属性。希望他们将来能让错误更清楚一些 c: