如果有人想更具体地执行以下步骤
1.添加此日期扩展
extension Date {
/// Returns the amount of years from another date
func years(from date: Date) -> Int {
return Calendar.current.dateComponents([.year], from: date, to: self).year ?? 0
}
/// Returns the amount of months from another date
func months(from date: Date) -> Int {
return Calendar.current.dateComponents([.month], from: date, to: self).month ?? 0
}
/// Returns the amount of weeks from another date
func weeks(from date: Date) -> Int {
return Calendar.current.dateComponents([.weekOfMonth], from: date, to: self).weekOfMonth ?? 0
}
/// Returns the amount of days from another date
func days(from date: Date) -> Int {
return Calendar.current.dateComponents([.day], from: date, to: self).day ?? 0
}
/// Returns the amount of hours from another date
func hours(from date: Date) -> Int {
return Calendar.current.dateComponents([.hour], from: date, to: self).hour ?? 0
}
/// Returns the amount of minutes from another date
func minutes(from date: Date) -> Int {
return Calendar.current.dateComponents([.minute], from: date, to: self).minute ?? 0
}
/// Returns the amount of seconds from another date
func seconds(from date: Date) -> Int {
return Calendar.current.dateComponents([.second], from: date, to: self).second ?? 0
}
/// Returns the amount of nanoseconds from another date
func nanoseconds(from date: Date) -> Int {
return Calendar.current.dateComponents([.nanosecond], from: date, to: self).nanosecond ?? 0
}
/// Returns the a custom time interval description from another date
func offset(from date: Date) -> String {
var result: String = ""
if years(from: date) > 0 { return "\(years(from: date))y" }
if months(from: date) > 0 { return "\(months(from: date))M" }
if weeks(from: date) > 0 { return "\(weeks(from: date))w" }
if seconds(from: date) > 0 { return "\(seconds(from: date))" }
if days(from: date) > 0 { result = result + " " + "\(days(from: date)) D" }
if hours(from: date) > 0 { result = result + " " + "\(hours(from: date)) H" }
if minutes(from: date) > 0 { result = result + " " + "\(minutes(from: date)) M" }
if seconds(from: date) > 0 { return "\(seconds(from: date))" }
return ""
}
}
2.全局定义
fileprivate var timer: Timer?
3.在 viewDidLoad 或任何你想要的地方调用这个方法
override func viewDidLoad() {
super.viewDidLoad()
self.getRemainingTime()
}
4.用法
fileprivate func getRemainingTime() {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
let startDate = "2018-06-02 10:11:12"
let currentDate = dateFormatter.string(from: Date())
if currentDate != startDate {
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(calculateTime)), userInfo: nil, repeats: true)
RunLoop.current.add(timer!, forMode: RunLoopMode.commonModes)
timer?.fire()
}
else {
self.timer?.invalidate()
self.timer = nil
}
}
func calculateTime() {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
let stdate : String = "2018-06-02 10:11:12"
let startDate = dateFormatter.date(from: stdate)!
let currentDate = Date()
let strTimer : String = startDate.offset(from: currentDate)
if !strTimer.isEmpty {
let stDay: String = "\((Int(strTimer)! % 31536000) / 86400)"
let stHour: String = "\((Int(strTimer)! % 86400) / 3600)"
let stMin: String = "\((Int(strTimer)! % 3600) / 60)"
let stSec: String = "\(Int(strTimer)! % 60)"
yourLabelOutlet.text = "Start In :\(stDay) Days \(stHour) Hours \(stMin) Minutes \(stSec) Seconds"
}
}
像 Charm 一样工作您可以在 UI 端使用每个单独的字符串，
享受