can't use useState with typescript (Cannot find name 'useState')

Question

What is the problem with below code? I got warning by typescript when use useState

import * as React, { useState } from 'react'

const useForm = (callback: any | undefined) => {
  const [inputs, setInputs] = useState({}) //error: Cannot find name 'useState'.ts(2304)


  const handleInputChange = event => {
    event.persist()
    setInputs(inputs => ({
      ...inputs,
      [event.target.name]: event.target.value,
    }))
  }

  return {
    handleInputChange,
    inputs,
  }
}

export default useForm

https://codesandbox.io/s/react-typescript-starter-lmub8

Answer 1

您的导入语句无效。

您可以React像这样导入所有内容：

import * as React from 'react';

以及useState来自React对象的访问：

 const [inputs, setInputs] = React.useState({})

或导入React为默认值，仅部分导入其他名称：

import React, { useState } from 'react'

和useState以前一样的使用：

const [inputs, setInputs] = useState({});