react hook 之useState_const [uploading, setuploading] = usestate

react hook 之useState 

此为typescript版本

import { useState } from 'react';
 
const TestCom: React.FC = (props) => {
  const [loading, setLoading] = useState<boolean>(false);
  // setLoading就是改变loading值的方法
 
  return (
    <div>
      <button onClick={()=>{setLoading(true)}}>点击改变loading值</button>
    </div>
  )
}

react class组件版本

import React from 'react'
 
class TestCom extends React.Component {
  
  state = {
    loading: false
  }
 
 // 修改状态数据的值
 handlerChange=()=>{
   this.setState({
     loading: true
   })
 }
  
  // 模版
  render() {
    <div>
      <p>{this.state.loading}</p>
      <button onClick={this.handlerChange}>handlerChange</button>
    </div>
  }
}