组件的实现 importReact,{Component}from'react' exportdefaultclassCountTimeDownextendsComponent{ constructor(props){ super(props); this.state={ day:0, hour:0, minute:0, second:0 } } componentDidMount(){ if(this.props.endTime){ letendTime=this.props.endTime.replace(/-/g,"/"); this.countFun(endTime...