ios - 如何在我的标签上显示两个日期的时间偏移量(年、月、周...)？

Question

我在我的应用程序中收到 Use of unresolved identifier 'self'。看完this link ，我将代码包装在一个类中。

注意:我正在使用从 answer 获得的扩展在 S.O.

class SetDate {

    var seconds = date2.secondsFrom(date1)
    var minutes = date2.minutesFrom(date1)
    var hours = date2.hoursFrom(date1)
    var days = date2.daysFrom(date1)
    var weeks = date2.weeksFrom(date1)
    var months = date2.monthsFrom(date1)
    var years = date2.yearsFrom(date1)

    func setLabels(seconds,minute,hous,weeks,days,months,years) {
        self.SLabel.text = s
        self.MLabel.text = min
        self.HLabel.text = h
        self.WLabel.text = w
        self.DLabel.text = d
        self.MLabel.text = m
        self.YLabel.text = y
    }

    setLabels(seconds,minutes,hours,weeks,days,months,years)
}

我该如何解决这个问题？

Answer 1

我已经创建了一个新的扩展来为您将偏移分量输出为字符串:

import UIKit
extension NSDate {
    func yearsFrom(date:NSDate) -> Int{
        return NSCalendar.currentCalendar().components(.CalendarUnitYear, fromDate: date, toDate: self, options: nil).year
    }
    func monthsFrom(date:NSDate) -> Int{
        return NSCalendar.currentCalendar().components(.CalendarUnitMonth, fromDate: date, toDate: self, options: nil).month
    }
    func weeksFrom(date:NSDate) -> Int{
        return NSCalendar.currentCalendar().components(.CalendarUnitWeekOfYear, fromDate: date, toDate: self, options: nil).weekOfYear
    }
    func daysFrom(date:NSDate) -> Int{
        return NSCalendar.currentCalendar().components(.CalendarUnitDay, fromDate: date, toDate: self, options: nil).day
    }
    func hoursFrom(date:NSDate) -> Int{
        return NSCalendar.currentCalendar().components(.CalendarUnitHour, fromDate: date, toDate: self, options: nil).hour
    }
    func minutesFrom(date:NSDate) -> Int{
        return NSCalendar.currentCalendar().components(.CalendarUnitMinute, fromDate: date, toDate: self, options: nil).minute
    }
    func secondsFrom(date:NSDate) -> Int{
        return NSCalendar.currentCalendar().components(.CalendarUnitSecond, fromDate: date, toDate: self, options: nil).second
    }

    func offsetComponentsFrom(date:NSDate) -> (years:String,months:String,weeks:String,days:String,hours:String,minutes:String,seconds:String) {

        let yearsFromDate = yearsFrom(date)
        let years = "\(yearsFromDate) year" + {return yearsFromDate > 1 ? "s" : ""}()

        let monthsFromDate = monthsFrom(date)
        let months =  "\(monthsFromDate) month" + {return monthsFromDate > 1 ? "s" : ""}()

        let weeksFromDate = weeksFrom(date)
        let weeks = "\(weeksFromDate) week" + {return weeksFromDate > 1 ? "s" : ""}()

        let daysFromDate = daysFrom(date)
        let days =  "\(daysFromDate) day" + {return daysFromDate > 1 ? "s" : ""}()

        let hoursFromDate = hoursFrom(date)
        let hours =  "\(hoursFromDate) hour" + {return hoursFromDate > 1 ? "s" : ""}()

        let minutesFromDate = minutesFrom(date)
        let minutes = "\(minutesFromDate) minute" + {return minutesFromDate > 1 ? "s" : ""}()

        let secondsFromDate = secondsFrom(date)
        let seconds = "\(secondsFromDate) second" + {return secondsFromDate > 1 ? "s" : ""}()
        return (years,months,weeks,days, hours, minutes, seconds)
    }
}

测试

let date1 = NSCalendar.currentCalendar().dateWithEra(1, year: 2014, month: 11, day: 28, hour: 5, minute: 9, second: 0, nanosecond: 0)!
let date2 = NSCalendar.currentCalendar().dateWithEra(1, year: 2015, month: 8, day: 28, hour: 5, minute: 9, second: 0, nanosecond: 0)!

func setLabels() {
    let components = date2.offsetComponentsFrom(date1)
    let years = components.years       // "0 year"
    let months = components.months     // "9 months"
    let weeks = components.weeks       // "39 weeks"
    let days = components.days         // "273 days"
    let hours = components.hours       // "6553 hours"
    let minutes = components.minutes   // "393180 minutes"
    let seconds = components.seconds   // "23590800 seconds"

    // set your labels
    //
    // yearsLabel.text = years
    // monthsLabel.text = months
    // weeksLabel.text = weeks
    // daysLabel.text = days
    // hoursLabel.text = hours
    // minutesLabel.text = minutes
    // secondsLabel.text = seconds

}

setLabels()