我试图得到当前日期之间的差异作为NSDate()和日期从一个PHP时间();调用例如:NSDate(timeintervalsincerely eferencedate: 1417147270)。我怎样才能得到这两个日期之间的时间差呢?我想有一个函数，比较两个日期，如果(秒> 60)，那么它返回分钟，如果(分钟> 60)返回小时，如果(小时> 24)返回天，等等。
我该怎么做呢?
编辑:目前接受的答案完全符合我的想法。为了便于使用，我推荐使用它，以便以PHP time()函数使用的形式获取两个日期之间的时间。如果你不是特别熟悉PHP，这是1970年1月1日的时间，单位是秒。这对于PHP的后端是有益的。如果你正在使用像NodeJS这样的后端，你可能会考虑下面的其他选项。
当前回答
结合扩展+ DateComponentsFormatter从@leo-dabus的答案
Xcode 8.3•Swift 3.1
extension DateComponentsFormatter {
func difference(from fromDate: Date, to toDate: Date) -> String? {
self.allowedUnits = [.year,.month,.weekOfMonth,.day]
self.maximumUnitCount = 1
self.unitsStyle = .full
return self.string(from: fromDate, to: toDate)
}
}
let dateComponentsFormatter = DateComponentsFormatter()
dateComponentsFormatter.difference(from: Date(), to: Date(timeIntervalSinceNow: 4000000)) // "1 month"
其他回答
以下是我对上述Swift 3的回答。这是截至2016年11月，Xcode发布版本为8.2 Beta (8C23)。使用上述Sagar和Emin的一些建议，有时不得不让Xcode自动完成来建议语法。在这个测试版中，语法似乎真的发生了变化。我从一个DatePicker:
let calendar = NSCalendar.current as NSCalendar
let currentDate = Date()
let date1 = calendar.startOfDay(for: buyDate!)
let date2 = calendar.startOfDay(for: currentDate)
let flags = NSCalendar.Unit.day
let components = calendar.components(flags, from: date1, to: date2)
NSLog(" day= \(components.day)")
我在Leo Dabus的asnwer中添加了一个“长”版本，以防你想要一个字符串，说“2周前”而不是“2w”……
extension Date {
func offsetLong(from date: Date) -> String {
if years(from: date) > 0 {
return years(from: date) > 1 ? "\(years(from: date)) years ago" : "\(years(from: date)) year ago"
}
if months(from: date) > 0 {
return months(from: date) > 1 ? "\(months(from: date)) months ago" : "\(months(from: date)) month ago"
}
if weeks(from: date) > 0 {
return weeks(from: date) > 1 ? "\(weeks(from: date)) weeks ago" : "\(weeks(from: date)) week ago"
}
if days(from: date) > 0 {
return days(from: date) > 1 ? "\(days(from: date)) days ago" : "\(days(from: date)) day ago"
}
if hours(from: date) > 0 {
return hours(from: date) > 1 ? "\(hours(from: date)) hours ago" : "\(hours(from: date)) hour ago"
}
if minutes(from: date) > 0 {
return minutes(from: date) > 1 ? "\(minutes(from: date)) minutes ago" : "\(minutes(from: date)) minute ago"
}
if seconds(from: date) > 0 {
return seconds(from: date) > 1 ? "\(seconds(from: date)) seconds ago" : "\(seconds(from: date)) second ago"
}
return ""
}
}
func dateDiff(dateStr:String) -> String {
var f:NSDateFormatter = NSDateFormatter()
f.timeZone = NSTimeZone.localTimeZone()
f.dateFormat = "yyyy-M-dd'T'HH:mm:ss.SSSZZZ"
var now = f.stringFromDate(NSDate())
var startDate = f.dateFromString(dateStr)
var endDate = f.dateFromString(now)
var calendar: NSCalendar = NSCalendar.currentCalendar()
let calendarUnits = NSCalendarUnit.CalendarUnitWeekOfMonth | NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitHour | NSCalendarUnit.CalendarUnitMinute | NSCalendarUnit.CalendarUnitSecond
let dateComponents = calendar.components(calendarUnits, fromDate: startDate!, toDate: endDate!, options: nil)
let weeks = abs(dateComponents.weekOfMonth)
let days = abs(dateComponents.day)
let hours = abs(dateComponents.hour)
let min = abs(dateComponents.minute)
let sec = abs(dateComponents.second)
var timeAgo = ""
if (sec > 0){
if (sec > 1) {
timeAgo = "\(sec) Seconds Ago"
} else {
timeAgo = "\(sec) Second Ago"
}
}
if (min > 0){
if (min > 1) {
timeAgo = "\(min) Minutes Ago"
} else {
timeAgo = "\(min) Minute Ago"
}
}
if(hours > 0){
if (hours > 1) {
timeAgo = "\(hours) Hours Ago"
} else {
timeAgo = "\(hours) Hour Ago"
}
}
if (days > 0) {
if (days > 1) {
timeAgo = "\(days) Days Ago"
} else {
timeAgo = "\(days) Day Ago"
}
}
if(weeks > 0){
if (weeks > 1) {
timeAgo = "\(weeks) Weeks Ago"
} else {
timeAgo = "\(weeks) Week Ago"
}
}
print("timeAgo is===> \(timeAgo)")
return timeAgo;
}
结合扩展+ DateComponentsFormatter从@leo-dabus的答案
Xcode 8.3•Swift 3.1
extension DateComponentsFormatter {
func difference(from fromDate: Date, to toDate: Date) -> String? {
self.allowedUnits = [.year,.month,.weekOfMonth,.day]
self.maximumUnitCount = 1
self.unitsStyle = .full
return self.string(from: fromDate, to: toDate)
}
}
let dateComponentsFormatter = DateComponentsFormatter()
dateComponentsFormatter.difference(from: Date(), to: Date(timeIntervalSinceNow: 4000000)) // "1 month"
如果你的目的是获得两个日期之间的确切天数，你可以这样解决这个问题:
// Assuming that firstDate and secondDate are defined
// ...
var calendar: NSCalendar = NSCalendar.currentCalendar()
// Replace the hour (time) of both dates with 00:00
let date1 = calendar.startOfDayForDate(firstDate)
let date2 = calendar.startOfDayForDate(secondDate)
let flags = NSCalendarUnit.DayCalendarUnit
let components = calendar.components(flags, fromDate: date1, toDate: date2, options: nil)
components.day // This will return the number of day(s) between dates
