React中实现CSS过渡动画

index.css

.show{
    opacity: 1;
    transition: all 1s ease-in;
}

.hide{
    opacity: 0;
    transition: all 1s ease-in;
}

app.js

import React, { Component, Fragment } from 'react';
import './index.css'

class App extends Component{
    constructor(props){
        super(props)
        this.state={
            show:true
        }
        this.handleToggle = this.handleToggle.bind(this)
    }
    render(){
        return (
            <Fragment>
                 <div class={this.state.show?'show':'hide'}>hello world</div>
                 <button onClick={this.handleToggle}>toggle</button>
            </Fragment>
        )
    }

    handleToggle(){
        this.setState(()=>({
            show:!this.state.show
        }))
    }
}

export default App;