Question

在我的后端，我更新用户上次活动：

{ last_active: new Date().getTime() }

在前端，我是这样做的：

const statusexpire = props.last_active + 1000 * 60;
const currenttime = new Date().getTime();
    
useEffect(() => {
  if (currenttime > statusexpire) {
    socket.emit('deletelogged', props.id);
    console.log('deleted' + props.id)
  }
}, [currenttime, props.id]);

但是好像做错了什么，我试了几个例子都没有解决这个问题。

更新 console.log(currenttime, statusexpire) 的日志只是为了查看输出：

1616162621335 "161616127040960000"
UserItem.js:40 1616162621338 "161616262117760000"
UserItem.js:40 1616162621345 "161616127040960000"
UserItem.js:40 1616162621346 "161616262117760000"
UserItem.js:40 1616162621398 "161616127040960000"
UserItem.js:40 1616162621400 "161616262117760000"
UserItem.js:40 1616162621410 "161616127040960000"
UserItem.js:40 1616162621416 "161616262117760000"
UserItem.js:40 1616162621425 "161616127040960000"
UserItem.js:40 1616162621427 "161616262117760000"
UserItem.js:40 1616162621435 "161616127040960000"
UserItem.js:40 1616162621440 "161616262117760000"
UserItem.js:40 1616162621447 "161616127040960000"
UserItem.js:40 1616162621449 "161616262117760000"
UserItem.js:40 1616162621456 "161616127040960000"
UserItem.js:40 1616162621460 "161616262117760000"
UserItem.js:40 1616162621466 "161616127040960000"
UserItem.js:40 1616162621468 "161616262117760000"
UserItem.js:40 1616162621482 "161616127040960000"
UserItem.js:40 1616162621491 "161616262117760000"
UserItem.js:40 1616162621497 "161616127040960000"
UserItem.js:40 1616162621502 "161616262117760000"
UserItem.js:40 1616162621513 "161616127040960000"
UserItem.js:40 1616162621519 "161616262117760000"
UserItem.js:40 1616162621527 "161616127040960000"
UserItem.js:40 1616162621528 "161616262117760000"
UserItem.js:40 1616162621535 "161616127040960000"
UserItem.js:40 1616162621541 "161616262117760000"
UserItem.js:40 1616162621549 "161616127040960000"

Answer 1

似乎 props.last_active 是字符串。试试怎么样

const statusexpire = parseInt(props.last_active) + 1000 * 60;

Answer 2

问题与以下事实有关：props.last_active 不是数字而是字符串，因此 props.last_active + 1000 * 60 返回与 props.last_active 连接的 1000 * 60。

要解决，只需将 props.last_active 转换为整数，然后将其与 1000 * 60 相加：

const statusexpire = parseInt(props.last_active) + 1000 * 60;

javascript新日期获取时间无法比较它们

2 个答案: