react refs 实现人民币=＞美元的互相转换

实时获取真实dom元素

import React from "react"
import ReactDOM, { render } from "react-dom"

class Practiseref extends React.Component{
    changeTodollar=(e)=>{
        this.refs.myinputdollar.value=e.target.value*7
        if( this.refs.myinputdollar.value=="0"){
            this.refs.myinputdollar.value=""
        }
    }
    changeTormb=(e)=>{
        this.refs.myinputrmb.value=(e.target.value/7).toFixed(2)
        if( this.refs.myinputrmb.value=="0"){
            this.refs.myinputrmb.value=""
        }
    }
    render(){
        return(
            <div>
                人民币：<input type="text" ref="myinputrmb" onChange={this.changeTodollar}></input>
                美元：<input type="text" ref="myinputdollar" onChange={this.changeTormb}></input>
                
            </div>
        )
    }
}
export default Practiseref