Reactjs 如何在react中发生卸载组件错误时导航到另一页而不使用setState（）

我正在学习编写一个倒数计时类的应用程序，一切正常，但我有一个问题，每当我试图导航到另一个页面而不按暂停，我会得到错误“只能更新装载或装载组件，这通常意味着你调用了卸载组件上的setState”。这意味着什么，我如何修复它？事先非常感谢

import React from 'react';
import SubjectForm from './SubjectForm';
import {connect} from 'react-redux';
import {editSubject, removeSubject} from '../actions/subjectAction';

class StartPage extends React.Component{
    constructor(props){
        super(props);
        this.state={count:this.props.subject.hour*60*60+this.props.subject.minute*60,
                    name:'run',
                    alert:''
                    };    
        this.timer = null;
        this.stateChange=this.state.count
        this.originTime = this.props.subject.hour*60*60+this.props.subject.minute*60;
    }

    setStateCountdown=(num)=>{
        this.setState({count:num})
    }

    setStateAlert=(text)=>{
        this.setState({alert:text})
    }

    setStateButtonChange=(text)=>{
        this.setState({name:text})
    }

    begin=()=>{
        clearInterval(this.timer)
        this.timer=setInterval(()=>{
            this.stateChange--
            this.setStateCountdown(this.stateChange)
            let timeLeft=this.stateChange

            if(this.stateChange<0){
                this.setStateAlert('done');
                clearInterval(this.timer);
            return;
        }
            let hourleft = Math.floor(timeLeft / (60 * 60));
            let minuteleft = Math.floor((timeLeft % (60 * 60)) / 60);
            let secondleft = timeLeft % 60;
            this.setStateAlert(`you have ${hourleft} hour ${minuteleft} minute and ${secondleft} second until reaching your goal`);


        },1000);
    }
    pause=()=>{
        clearInterval(this.timer)  
        console.log(this.state.count) 
        if(this.state.count<this.originTime){
            this.setStateButtonChange('resume')
        }
    }

    reset=()=>{
        const pressConfirm = confirm('are you sure you want to reset?')
        if(pressConfirm===true){
            console.log(this.state.count)
            clearInterval(this.timer)
            this.stateChange=this.originTime;
            this.callbackFuncCountdown(this.stateChange)
            this.callbackFunctionButtonChange('run')
            this.callbackFunctionAlert('lets begin your study again')
        }
    }

    render(){
        return(
            <div>
            <SubjectForm subject={this.props.subject}/>
            <button onClick = {this.begin}>{this.state.name}</button>
            <button onClick = {this.pause}>pause</button>
            <button onClick = {this.reset}>reset</button>
            <h3>{this.state.alert}</h3>
            </div>
        );
    }
};

const mapStateToProps = (state,props)=>{
    return{
        subject: state.subjects.find((subject)=>subject.id===props.match.params.id)
    };
}

export default connect(mapStateToProps)(StartPage);

---

很抱歉代码太长。

导航到另一个页面卸载组件，但setInterval中的函数仍在运行，并试图更新卸载的组件状态。根据应用程序所需的行为，您有2个选项：

1-使用redux存储计时器并分派启动/暂停/停止操作 如果您导航，它将继续运行

---

2-组件中的clearInterval将卸载组件重置或停止计时器的方法如果您导航

谢谢，我将尝试两种方法，希望我能在接下来的几天内学会如何执行，至少我现在有了一个方向