我如何比较Swift 3中的两个日期(NSDate)并获得它们之间的日子？

Question

如何比较Swift 3中的两个日期？我找到了许多其他Swift版本的解决方案,但它们对我不起作用.

let clickedDay:String = currentcell.DayLabel.text!
    let currentDate = NSDate()
    let currentDay = "" //want the current day
    let dateFormatter = DateFormatter()        
    var dateAsString = ""        
    if Int(clickedDay)! < 10 {            
        dateAsString = "0" + clickedDay + "-11-2016 GMT"
    }
    else {            
        dateAsString = clickedDay + "-11-2016 GMT"
    }

    dateFormatter.dateFormat = "dd-MM-yyyy zzz"
    let clickedDate = dateFormatter.date(from: dateAsString)        
    if currentDate as Date >= clickedDate! as Date {

        return true
    }
    else {
        //Want to get the days between the currentDate and clickedDate
        let daysLeft = ""
    }

我比较了拖曳日期,但我想要那些拖曳日期之间的日子.有人可以帮我吗？谢谢,问候

补充:如果我有日期22.11.2016和当前日期(现在是18.11.2016)我想要它之间的日子(在这种情况下是4)

Answer 1

只需Date像这样进行扩展,并在几天内获得差异.

extension Date {
    func daysBetweenDate(toDate: Date) -> Int {
        let components = Calendar.current.dateComponents([.day], from: self, to: toDate)
        return components.day ?? 0
    }
}

现在使用这个扩展名

let numOfDays = fromDate.daysBetweenDate(toDate: toDate)

您可以使用DateFormatter像这样将String转换为Date.

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy"
dateFormatter.timeZone = TimeZone(abbreviation: "GMT")
let date = dateFormatter.date(from: "18-11-2016")