Xcode 圣诞节倒计时

Question

我正在寻找 Xcode 的可能性，以便在圣诞节前几天获得标签计数镇。我试着倒数与 NSDate 基金会的日子，但没有找到解决方案:(

这个倒计时是一个礼物或某人，我感谢您提供的每个示例代码！

提前致谢！本杰明

我试过的代码来自一个较旧的视频，但对我来说没有用...有人能告诉我为什么以及如何修复它吗？

代码：

import UIKit

class StartViewController: UIViewController {

@IBOutlet weak var dateLabelOutlet: UILabel!

let formatter = DateFormatter()

let userCalendar = NSCalendar.current

let requestedComponents: NSCalendar.Unit = [
    NSCalendar.Unit.Month,
    NSCalendar.Unit.Day,
    NSCalendar.Unit.Hour,
    NSCalendar.Unit.Minute,
    NSCalendar.Unit.Second
]

func printTime(){
    formatter.dateFormat = "MM/dd/yy hh:mm:ss a"
    let startTime = NSDate()
    let endTime = formatter.date(from: "12/24/18 12:00:00 a")

    let timeDifference = userCalendar.dateComponents(requestedComponents, from: startTime, to: endTime!, options: [])     
    }
}

Answer 1

此方法计算并打印从今天到下一个圣诞节的天数

func printDays() {
    // create date components of 12/24
    let xmasComponents = DateComponents(month: 12, day: 24)
    // get next occurrence 
    let nextXmas = Calendar.current.nextDate(after: Date(), matching: xmasComponents, matchingPolicy: .strict)!
    // calculate number of days
    let daysUntilXmas = Calendar.current.dateComponents([.day], from: Date() , to: nextXmas).day!
    print("Christmas is in \(daysUntilXmas) days")
}

Xcode 圣诞节倒计时

Xcode Countdown for days until Christmas

ios

swift4

xcode10