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
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 ""
}
}
其他回答
你问:
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。
我假设您正在尝试构建两个日期之间经过时间的字符串表示。而不是自己写代码来做这件事，苹果已经有了一个专门设计来做这件事的类。也就是说，使用DateComponentsFormatter，将allowedUnits设置为对你的应用有意义的任何值，将unitsStyle设置为你想要的任何值(例如.full)，然后调用string(from:to:)。
例如，在Swift 3中:
let previousDate = ...
let now = Date()
let formatter = DateComponentsFormatter()
formatter.unitsStyle = .full
formatter.allowedUnits = [.month, .day, .hour, .minute, .second]
formatter.maximumUnitCount = 2 // often, you don't care about seconds if the elapsed time is in months, so you'll set max unit to whatever is appropriate in your case
let string = formatter.string(from: previousDate, to: now)
这也将本地化对应于相关设备的字符串。
或者，在Swift 2.3中:
let previousDate = ...
let now = NSDate()
let formatter = NSDateComponentsFormatter()
formatter.unitsStyle = .Full
formatter.allowedUnits = [.Month, .Day, .Hour, .Minute, .Second]
formatter.maximumUnitCount = 2
let string = formatter.stringFromDate(previousDate, toDate: now)
如果您正在寻找实际的数值，只需使用dateComponents。例如，在Swift 3中:
let components = Calendar.current.dateComponents([.month, .day, .hour, .minute, .second], from: previousDate, to: now)
或者，在Swift 2.3中:
let components = NSCalendar.currentCalendar().components([.Month, .Day, .Hour, .Minute, .Second], fromDate: previousDate, toDate: now, options: [])
对Swift 3.0略有修改的代码
let calendar = NSCalendar.current as NSCalendar
// Replace the hour (time) of both dates with 00:00
let date1 = calendar.startOfDay(for: startDateTime)
let date2 = calendar.startOfDay(for: endDateTime)
let flags = NSCalendar.Unit.day
let components = calendar.components(flags, from: date1, to: date2, options: [])
return components.day!
如果有人需要显示所有的时间单位，如“小时分秒”，而不仅仅是“小时”。假设两个日期的时差是1小时59分20秒。该功能将显示“1h 59m 20s”。
下面是我的Objective-C代码:
extension NSDate {
func offsetFrom(date: NSDate) -> String {
let dayHourMinuteSecond: NSCalendarUnit = [.Day, .Hour, .Minute, .Second]
let difference = NSCalendar.currentCalendar().components(dayHourMinuteSecond, fromDate: date, toDate: self, options: [])
let seconds = "\(difference.second)s"
let minutes = "\(difference.minute)m" + " " + seconds
let hours = "\(difference.hour)h" + " " + minutes
let days = "\(difference.day)d" + " " + hours
if difference.day > 0 { return days }
if difference.hour > 0 { return hours }
if difference.minute > 0 { return minutes }
if difference.second > 0 { return seconds }
return ""
}
}
在Swift 3+中:
extension Date {
func offsetFrom(date: Date) -> String {
let dayHourMinuteSecond: Set<Calendar.Component> = [.day, .hour, .minute, .second]
let difference = NSCalendar.current.dateComponents(dayHourMinuteSecond, from: date, to: self)
let seconds = "\(difference.second ?? 0)s"
let minutes = "\(difference.minute ?? 0)m" + " " + seconds
let hours = "\(difference.hour ?? 0)h" + " " + minutes
let days = "\(difference.day ?? 0)d" + " " + hours
if let day = difference.day, day > 0 { return days }
if let hour = difference.hour, hour > 0 { return hours }
if let minute = difference.minute, minute > 0 { return minutes }
if let second = difference.second, second > 0 { return seconds }
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;
}
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 ""
}
}
