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
Swift 5.1•iOS 13
你可以使用苹果在iOS 13中引入的RelativeDateFormatter。
let exampleDate = Date().addingTimeInterval(-15000)
let formatter = RelativeDateTimeFormatter()
formatter.unitsStyle = .full
let relativeDate = formatter.localizedString(for: exampleDate, relativeTo: Date())
print(relativeDate) // 4 hours ago
参见如何使用RelativeDateTimeFormatter显示相对日期和时间。
对于XCode版本8.3.3和Swift 3.0:
let dateFormatter = DateFormatter()
dateFormatter.dateStyle = .medium
dateFormatter.timeStyle = .short
var beginDate = "2017-08-24 12:00:00"
var endDate = "2017-09-07 12:00:00"
let startDateTime = dateFormatter.date(from: beginDate) //according to date format your date string
print(startDateTime ?? "") //Convert String to Date
let endDateTime = dateFormatter.date(from: endDate) //according to date format your date string
print(endDateTime ?? "") //Convert String to Date
let dateComponentsFormatter = DateComponentsFormatter()
dateComponentsFormatter.allowedUnits = [NSCalendar.Unit.minute,NSCalendar.Unit.hour,NSCalendar.Unit.day]
let interval = endDateTime!.timeIntervalSince(startDateTime!)
var diff = dateComponentsFormatter.string(from: interval)!
print(diff)
var day_i = 0
var hour_i = 0
var min_i = 0
if (diff.contains("d"))
{
let day = diff.substring(to: (diff.range(of: "d")?.lowerBound)!)
day_i = Int(day)!
print ("day --> \(day_i)")
diff = diff.substring(from:(diff.range(of : " ")?.upperBound )!)
print(diff)
}
let hour = diff.substring(to: (diff.range(of : ":")?.lowerBound )!)
hour_i = Int(hour)!
print ("hour --> \(hour_i)")
let min = diff.substring(from: (diff.range(of : ":")?.upperBound )!)
min_i = Int(min)!
print ("min --> \(min_i)")
import Foundation
extension DateComponents {
func dateComponentsToTimeString() -> String {
var hour = "\(self.hour!)"
var minute = "\(self.minute!)"
var second = "\(self.second!)"
if self.hour! < 10 { hour = "0" + hour }
if self.minute! < 10 { minute = "0" + minute }
if self.second! < 10 { second = "0" + second }
let str = "\(hour):\(minute):\(second)"
return str
}
}
extension Date {
func offset(from date: Date)-> DateComponents {
let components = Set<Calendar.Component>([.second, .minute, .hour, .day, .month, .year])
let differenceOfDate = Calendar.current.dateComponents(components, from: date, to: self)
return differenceOfDate
}
}
Use:
var durationString: String {
return self.endTime.offset(from: self.startTime).dateComponentsToTimeString()
}
使用Swift 3，根据您的需要，您可以选择以下两种方式之一来解决您的问题。
1. 向用户显示两个日期之间的差异
你可以使用DateComponentsFormatter为你的应用程序界面创建字符串。DateComponentsFormatter有一个maximumUnitCount属性，声明如下:
var maximumUnitCount: Int { get set }
使用此属性可限制结果字符串中显示的单位数量。例如，将此属性设置为2，而不是“1h 10m, 30s”，生成的字符串将是“1h 10m”。当空间受限或希望将值舍入到最近的大单位时，请使用此属性。
通过将maximumUnitCount的值设置为1，可以保证仅以一个DateComponentsFormatter的单位(年、月、日、小时或分钟)显示差异。
下面的Playground代码显示了如何显示两个日期之间的差异:
import Foundation
let oldDate = Date(timeIntervalSinceReferenceDate: -16200)
let newDate = Date(timeIntervalSinceReferenceDate: 0)
let dateComponentsFormatter = DateComponentsFormatter()
dateComponentsFormatter.allowedUnits = [NSCalendar.Unit.year, .month, .day, .hour, .minute]
dateComponentsFormatter.maximumUnitCount = 1
dateComponentsFormatter.unitsStyle = DateComponentsFormatter.UnitsStyle.full
let timeDifference = dateComponentsFormatter.string(from: oldDate, to: newDate)
print(String(reflecting: timeDifference)) // prints Optional("5 hours")
注意，DateComponentsFormatter对结果进行四舍五入。因此，4小时和30分钟的差异将显示为5小时。
如果你需要重复这个操作，你可以重构你的代码:
import Foundation
struct Formatters {
static let dateComponentsFormatter: DateComponentsFormatter = {
let dateComponentsFormatter = DateComponentsFormatter()
dateComponentsFormatter.allowedUnits = [NSCalendar.Unit.year, .month, .day, .hour, .minute]
dateComponentsFormatter.maximumUnitCount = 1
dateComponentsFormatter.unitsStyle = DateComponentsFormatter.UnitsStyle.full
return dateComponentsFormatter
}()
}
extension Date {
func offset(from: Date) -> String? {
return Formatters.dateComponentsFormatter.string(from: oldDate, to: self)
}
}
let oldDate = Date(timeIntervalSinceReferenceDate: -16200)
let newDate = Date(timeIntervalSinceReferenceDate: 0)
let timeDifference = newDate.offset(from: oldDate)
print(String(reflecting: timeDifference)) // prints Optional("5 hours")
2. 在不设置格式的情况下获取两个日期之间的差异
如果不需要将两个日期之间的差异格式化显示给用户，则可以使用Calendar。日历有一个方法dateComponents(_:from:to:)，它有以下声明:
func dateComponents(_ components: Set<Calendar.Component>, from start: Date, to end: Date) -> DateComponents
返回两个日期的差值。
下面使用dateComponents(_:from:to:)的Playground代码展示了如何通过只返回一种日历类型的差异来检索两个日期之间的差异。组件(年、月、日、小时或分钟)。
import Foundation
let oldDate = Date(timeIntervalSinceReferenceDate: -16200)
let newDate = Date(timeIntervalSinceReferenceDate: 0)
let descendingOrderedComponents = [Calendar.Component.year, .month, .day, .hour, .minute]
let dateComponents = Calendar.current.dateComponents(Set(descendingOrderedComponents), from: oldDate, to: newDate)
let arrayOfTuples = descendingOrderedComponents.map { ($0, dateComponents.value(for: $0)) }
for (component, value) in arrayOfTuples {
if let value = value, value > 0 {
print(component, value) // prints hour 4
break
}
}
如果你需要重复这个操作，你可以重构你的代码:
import Foundation
extension Date {
func offset(from: Date) -> (Calendar.Component, Int)? {
let descendingOrderedComponents = [Calendar.Component.year, .month, .day, .hour, .minute]
let dateComponents = Calendar.current.dateComponents(Set(descendingOrderedComponents), from: from, to: self)
let arrayOfTuples = descendingOrderedComponents.map { ($0, dateComponents.value(for: $0)) }
for (component, value) in arrayOfTuples {
if let value = value, value > 0 {
return (component, value)
}
}
return nil
}
}
let oldDate = Date(timeIntervalSinceReferenceDate: -16200)
let newDate = Date(timeIntervalSinceReferenceDate: 0)
if let (component, value) = newDate.offset(from: oldDate) {
print(component, value) // prints hour 4
}
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 ""
}
}
