react/typescript:参数'props'隐含有'any'类型错误

Question

当我从react-bootstrap尝试这个示例代码时,我不断收到错误,例如"参数'上下文'隐含地具有'任意'类型;"类型'Readonly <{}>'上不存在属性'值'."

在form.tsx中:

class FormExample extends React.Component {
  constructor(props, context) {
    super(props, context);

    this.handleChange = this.handleChange.bind(this);

    this.state = {
      value: ''
    };
  }

  getValidationState() {
    const length = this.state.value.length;
    if (length > 10) return 'success';
    else if (length > 5) return 'warning';
    else if (length > 0) return 'error';
    return null;
  }

  handleChange(e) {
    this.setState({ value: e.target.value });
  }

  render() {
    return (
      <form>
        <FormGroup
          controlId="formBasicText"
          validationState={this.getValidationState()}
        >
          <ControlLabel>Working example with validation</ControlLabel>
          <FormControl
            type="text"
            value={this.state.value}
            placeholder="Enter text"
            onChange={this.handleChange}
          />
          <FormControl.Feedback />
          <HelpBlock>Validation is based on string length.</HelpBlock>
        </FormGroup>
      </form>
    );
  }
}

export default FormExample;

在Jumbo.tsx:

const Jumbo = () => (
   <FormExample />
);

Answer 1

在typeScript中你应该安装@ types/react,在扩展React.Component时你需要指定props和state类型.这是一个例子

import * as React from 'react'

interface Props {
  ... // your props validation
}

interface State {
  ... // state types
}

class FormExample extends React.Component<Props, State> {... }

希望它会对你有所帮助

Answer 2

在我的例子中,指定构造函数参数的类型解决了这个问题.

class Clock extends React.Component<any, any> {

    constructor(props: any) {
        super(props);
    }
}

Answer 3

我刚刚在功能组件上收到此错误。

为了获取诸如props.children自定义道具之类的信息，您应该执行以下操作。

import { FunctionComponent } from 'react';

const Layout: FunctionComponent<{ hello: string }> = props => (
  <div style={layoutStyle}>
    <Header />
    {props.hello}
    {props.children}
  </div>
);