Question

我有以下代码：

//Age

@IBOutlet weak var daysLabel: UILabel!
@IBOutlet weak var monthsLabel: UILabel!
@IBOutlet weak var yearsLabel: UILabel!

@IBAction func birthday(sender:AnyObject){
    var dateComponents = NSDateComponents()

    dateComponents.day = 19
    dateComponents.month = 12
    dateComponents.year = 2015

    let certainDate = NSCalendar(identifier: NSCalendarIdentifierGregorian)!.dateFromComponents(dateComponents)!
    let durationDateComponents = NSCalendar(identifier: NSCalendarIdentifierGregorian)!.components( [.Year, .Month, .Day, .Hour, .Minute, .Second], fromDate: NSDate(), toDate:certainDay, options: [])

    yearsLabel.text = "\(durationDateComponents.year)"
    monthsLabel.text = "\(durationDateComponents.month)"
    daysLabel.text = "\(durationDateComponents.day)"
}

此代码计算自那天起的天数，但它不会倒计时，为什么？我如何实现这一目标？

Answer 1

我不完全理解你的问题，但这段代码会告诉你我下个生日的日子。：）

let now = NSDate()
let birthdayDay = 23
let birthdayMonth = 8
let calendar = NSCalendar.currentCalendar()
let thisYear = calendar.component(.Year, fromDate: now)
let bdayComponents = NSDateComponents()
bdayComponents.day = birthdayDay
bdayComponents.month = birthdayMonth
bdayComponents.year = thisYear
var bdayDate = calendar.dateFromComponents(bdayComponents)!
var timeLeft = bdayDate.timeIntervalSinceDate(now)

if (timeLeft < 0) {
    bdayComponents.year = thisYear + 1
    bdayDate = calendar.dateFromComponents(bdayComponents)!
    timeLeft = bdayDate.timeIntervalSinceDate(now)
}

let componentsUntilBday = calendar.components(.Day, fromDate: now, toDate: bdayDate, options: NSCalendarOptions.MatchStrictly)
print("Scott's birthday is in \(componentsUntilBday.day) days!")

更新了在评论中使用建议的代码

如何让此代码显示直到事件发生的几天，而不是事件发生后的几天

1 个答案: