基本上,就像标题说的那样。我想知道如何添加1天的NSDate。
如果它是:
21st February 2011
它将变成:
22nd February 2011
或者如果它是:
31st December 2011
它将变成:
1st January 2012.
基本上,就像标题说的那样。我想知道如何添加1天的NSDate。
如果它是:
21st February 2011
它将变成:
22nd February 2011
或者如果它是:
31st December 2011
它将变成:
1st January 2012.
当前回答
在Swift 4或Swift 5中,你可以使用like bellow:
let date = Date()
let yesterday = Calendar.current.date(byAdding: .day, value: -1, to: date)
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let yesterday_date = dateFormatter.string(from: yesterday!)
print("yesterday->",yesterday_date)
输出:
Current date: 2020-03-02
yesterday date: 2020-03-01
其他回答
基于highmaintenance的回答和vikingosegundo的评论,一个工作的Swift 3+实现。这个日期扩展也有额外的选项来改变年,月和时间:
extension Date {
/// Returns a Date with the specified amount of components added to the one it is called with
func add(years: Int = 0, months: Int = 0, days: Int = 0, hours: Int = 0, minutes: Int = 0, seconds: Int = 0) -> Date? {
let components = DateComponents(year: years, month: months, day: days, hour: hours, minute: minutes, second: seconds)
return Calendar.current.date(byAdding: components, to: self)
}
/// Returns a Date with the specified amount of components subtracted from the one it is called with
func subtract(years: Int = 0, months: Int = 0, days: Int = 0, hours: Int = 0, minutes: Int = 0, seconds: Int = 0) -> Date? {
return add(years: -years, months: -months, days: -days, hours: -hours, minutes: -minutes, seconds: -seconds)
}
}
如果按照OP的要求只增加一天,则用法如下:
let today = Date() // date is then today for this example
let tomorrow = today.add(days: 1)
在swift中,您可以在NSDate中添加扩展方法
extension NSDate {
func addNoOfDays(noOfDays:Int) -> NSDate! {
let cal:NSCalendar = NSCalendar.currentCalendar()
cal.timeZone = NSTimeZone(abbreviation: "UTC")!
let comps:NSDateComponents = NSDateComponents()
comps.day = noOfDays
return cal.dateByAddingComponents(comps, toDate: self, options: nil)
}
}
你可以用这个
NSDate().addNoOfDays(3)
使用以下代码:
NSDate *now = [NSDate date];
int daysToAdd = 1;
NSDate *newDate1 = [now dateByAddingTimeInterval:60*60*24*daysToAdd];
As
addTimeInterval
现在已弃用。
字符串扩展:转换String_Date >日期
extension String{
func DateConvert(oldFormat:String)->Date{ // format example: yyyy-MM-dd HH:mm:ss
let isoDate = self
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX") // set locale to reliable US_POSIX
dateFormatter.dateFormat = oldFormat
return dateFormatter.date(from:isoDate)!
}
}
日期扩展:转换日期>字符串
extension Date{
func DateConvert(_ newFormat:String)-> String{
let formatter = DateFormatter()
formatter.dateFormat = newFormat
return formatter.string(from: self)
}
}
日期扩展:获取+/-日期
extension String{
func next(day:Int)->Date{
var dayComponent = DateComponents()
dayComponent.day = day
let theCalendar = Calendar.current
let nextDate = theCalendar.date(byAdding: dayComponent, to: Date())
return nextDate!
}
func past(day:Int)->Date{
var pastCount = day
if(pastCount>0){
pastCount = day * -1
}
var dayComponent = DateComponents()
dayComponent.day = pastCount
let theCalendar = Calendar.current
let nextDate = theCalendar.date(byAdding: dayComponent, to: Date())
return nextDate!
}
}
用法:
let today = Date()
let todayString = "2020-02-02 23:00:00"
let newDate = today.DateConvert("yyyy-MM-dd HH:mm:ss") //2020-02-02 23:00:00
let newToday = todayString.DateConvert(oldFormat: "yyyy-MM-dd HH:mm:ss")//2020-02-02
let newDatePlus = today.next(day: 1)//2020-02-03 23:00:00
let newDateMinus = today.past(day: 1)//2020-02-01 23:00:00
参考:来自多重问题 我如何添加1天到一个NSDate? 数学函数转换正整数为负和负到正? 将NSString转换为NSDate(然后再转换回来)
对于swift 2.2:
let today = NSDate()
let tomorrow = NSCalendar.currentCalendar().dateByAddingUnit(
.Day,
value: 1,
toDate: today,
options: NSCalendarOptions.MatchStrictly)
希望这能帮助到一些人!