ReactNative 退出到后台一定时间之后，跳转到登录界面

****实现长时间不操作应用，可以自定义多长时间，直接跳转到登录界面，登录之后才能再进行操作****
let pTimes;
let BACK_TO_LOGIN_TIME = 120；
constructor(props) {
   super(props);
   this.state={
       currentAppState:AppState.currentState,
   }
}

componentDidMount() {
    AppState.addEventListener('change', this.handleAppStateChange);
    pTimes =-1;
}

componentWillUnmount() {
    AppState.removeEventListener('change', this.handleAppStateChange);
}

handleAppStateChange = (nextAppState) => {
    if (this.state.currentAppState.match(/inactive|background/) && nextAppState === 'active') {
        let tempTime = getCurrentTime();
        let waste = tempTime -pTimes;
        console.log('----'+preTimes+'----waste:' + waste)
        console.log('BACK_TO_LOGIN_TIME====='+BACK_TO_LOGIN_TIME)
        if (waste > BACK_TO_LOGIN_TIME) {
            InteractionManager.runAfterInteractions(()=>{
                this.props.navigator.resetTo({
                    component:Login,
                    name:'Login',
                })
            })
        toastShort('长时间未操作，需要重新登录')
        console.log('AppState：'+'It's too late,login again')
        }else{
            console.log('AppState：'+'回来的很及时')
        }
        console.log('AppState:'+'现在在前台')
    }else{
        //前台切换至后台
        console.log('AppState:'+'现在在后台')
        preTimes = getCurrentTime();
    }
    this.setState({ currentAppState:nextAppState});
    console.log('pTimes：'+pTimes);
}

//返回从1970年1月1日至今的毫秒数
export function getCurrentTime(){
    let date = new Date();
    return date.getTime();

}