Typescript输入onchange event.target.value

在我的react和typescript应用程序中，我使用:

onChange={(e) => data.motto = (e.target as any).value}

我如何正确地定义类的类型，这样我就不必用任何类型系统来破解我的方法?

export interface InputProps extends React.HTMLProps<Input> {
...

}

export class Input extends React.Component<InputProps, {}> {
}

如果我放target: {value: string};我得到:

ERROR in [default] /react-onsenui.d.ts:87:18
Interface 'InputProps' incorrectly extends interface 'HTMLProps<Input>'.
  Types of property 'target' are incompatible.
    Type '{ value: string; }' is not assignable to type 'string'.

当前回答

在TypeScript中使用的正确方法是

  handleChange(e: React.ChangeEvent<HTMLInputElement>) {
    // No longer need to cast to any - hooray for react!
    this.setState({temperature: e.target.value});
  }

  render() {
        ...
        <input value={temperature} onChange={this.handleChange} />
        ...
    );
  }

遵循完整的类，更好地理解:

import * as React from "react";

const scaleNames = {
  c: 'Celsius',
  f: 'Fahrenheit'
};


interface TemperatureState {
   temperature: string;
}

interface TemperatureProps {
   scale: string;

}

class TemperatureInput extends React.Component<TemperatureProps, TemperatureState> {
  constructor(props: TemperatureProps) {
    super(props);
    this.handleChange = this.handleChange.bind(this);
    this.state = {temperature: ''};
  }

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


  handleChange(e: React.ChangeEvent<HTMLInputElement>) {
    // No longer need to cast to any - hooray for react!
    this.setState({temperature: e.target.value});
  }

  render() {
    const temperature = this.state.temperature;
    const scale = this.props.scale;
    return (
      <fieldset>
        <legend>Enter temperature in {scaleNames[scale]}:</legend>
        <input value={temperature} onChange={this.handleChange} />
      </fieldset>
    );
  }
}

export default TemperatureInput;

2018-04-13 15:08:06

其他回答

import { NativeSyntheticEvent, TextInputChangeEventData,} from 'react-native';



  // Todo in java script
 const onChangeTextPassword = (text : any) => {
    setPassword(text);
  }

// Todo在类型脚本中使用这个

  const onChangeTextEmail = ({ nativeEvent: { text },}: NativeSyntheticEvent<TextInputChangeEventData>) => {
    console.log("________ onChangeTextEmail _________ "+ text);
    setEmailId(text);
  };


 <TextInput
          style={{ width: '100%', borderBottomWidth: 1, borderBottomColor: 'grey', height: 40, }}
          autoCapitalize="none"
          returnKeyType="next"
          maxLength={50}
          secureTextEntry={false}
          onChange={onChangeTextEmail}
          value={emailId}
          defaultValue={emailId}
          
        />

2021-09-20 13:33:37

当使用子组件时，我们像这样检查类型。

父组件:

export default () => {

  const onChangeHandler = ((e: React.ChangeEvent<HTMLInputElement>): void => {
    console.log(e.currentTarget.value)
  }

  return (
    <div>
      <Input onChange={onChangeHandler} />
    </div>
  );
}

子组件:

type Props = {
  onChange: (e: React.ChangeEvent<HTMLInputElement>) => void
}

export Input:React.FC<Props> ({onChange}) => (
  <input type="tex" onChange={onChange} />
)

2020-07-19 03:27:36

如果你这样做，你不需要输入:

<input onChange={(event) => { setValue(e.target.value) }} />

因为如果你直接在html标签中使用箭头函数设置了一个新值，typescript将默认理解事件的类型。

2021-07-20 14:20:38

const event = { target: { value: 'testing' } as HTMLInputElement };
handleChangeFunc(event as ChangeEvent<HTMLInputElement>);

这对我很有用。

2022-09-19 02:55:15

const handleChange = (
    e: ChangeEvent<HTMLInputElement>
  ) => {
    const { name, value } = e.target;
    this.setState({ ...currentState, [name]: value });
  };

您可以将此应用于表单组件中的每个输入元素

2022-11-24 19:04:30

Typescript输入onchange event.target.value

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