ios - 在日期之间执行操作数

Question

我正在做一个秒表，并且需要在事件持续到结束时显示计时器。承认事件于晚上 8 点开始，当前日期为晚上 9.30，秒表显示 01:30:00，并将继续滴答作响，直到 end_time 到达。这是我的代码，我需要一种方法来为 currentTime 提供 currentDate-start_time 的值

var currentTime = 0

func printTime() {
    let formatter = DateFormatter()
    formatter.dateFormat = "dd/MM/yyyy"
    let start_time = self.eventArray[self.clubId!]?.start_time
    let end_time = self.eventArray[self.clubId!]?.end_time
    self.currentTime = currentDate - start_time


    if(currentDate?.compare(start_time!) == .orderedAscending && currentDate?.compare(end_time!) == .orderedAscending)
    {
        if(timer != nil)
        {
            timer?.invalidate()
            timer = nil
        }else
        {
            timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true, block: { _ in
                self.currentTime += 1
                let hoursPortion = String(format: "%02d", self.currentTime / 60)
                let minutesPortion = String(format: "%02d", self.currentTime / 60)
                let secondsPortion = String(format: "%02d", self.currentTime % 60)
                self.sinceBandeauLabel.text = "\(hoursPortion):\(minutesPortion):\(secondsPortion)"
            })

    }

    }

Answer 1

如果start_time是Date，那么您可以使用currentDate.timeIntervalSince(start_time)。