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在Swift中将字符串转换为日期

swiftnsdatensdateformatter
226

如何将字符串"2016-04-14T10:44:00+0000"转换为NSDate并仅保留年、月、日和小时？

其中的T让我在处理日期时感到困惑。

你只想要年份、月份、日期和小时，对吗？ - Mitul Marsoniya
可能是重复问题：如何在Swift中将字符串转换为NSDate。 - Fogmeister
18个回答
392

  • Convert the ISO8601 string to date

      let isoDate = "2016-04-14T10:44:00+0000"

  let dateFormatter = DateFormatter()
  dateFormatter.locale = Locale(identifier: "en_US_POSIX") // set locale to reliable US_POSIX
  dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
  let date = dateFormatter.date(from:isoDate)!

  • Get the date components for year, month, day and hour from the date

      let calendar = Calendar.current
  let components = calendar.dateComponents([.year, .month, .day, .hour], from: date)

  • Finally create a new Date object and strip minutes and seconds

      let finalDate = calendar.date(from:components)

还有一个方便的格式化程序ISO8601DateFormatter，它在iOS 10 / macOS 10.12中被引入：

let isoDate = "2016-04-14T10:44:00+0000"

let dateFormatter = ISO8601DateFormatter()
let date = dateFormatter.date(from:isoDate)!
8
"yyyy-MM-dd'T'HH:mm:ssZ" 中的 Z 解决了我的问题。 - asheyla
@Sneha 你得到了什么？代码崩溃了吗？那么可能是isoDate字符串与格式不匹配。如果您传递有效日期，则第二部分应在任何情况下都能正常工作。 - vadian
@vadian 我想要日期格式为dd-mm-yyyy，但我得到的是2017-03-10 18:30:00 +0000，而不是10-03-2017。 - Sneha
让我们在聊天中继续这个讨论。 - Sneha
3
一体化：ISO8601DateFormatter().date(from:"你的字符串")！ - Mike Irving
显示剩余14条评论
56
尝试以下日期格式。
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZZZ"
let date = dateFormatter.dateFromString(strDate)

对于Swift 4.1：

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ssZZZ"
let date = dateFormatter.date(from: strDate)
21
尝试过了，执行后返回空值。 - asheyla
3
无法将类型为'String'的值强制转换为类型为'Date'的值。 - J A S K I E R
有人在日期字符串检查中返回了nil，请检查我的答案。 - Ucdemir
37
在Swift 4.1中，您可以执行以下操作：
func getDate() -> Date? {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
    dateFormatter.timeZone = TimeZone.current
    dateFormatter.locale = Locale.current
    return dateFormatter.date(from: "2015-04-01T11:42:00") // replace Date String
}
我该如何在label.text中使用它？ - Emre Değirmenci
@ Emre Değirmenci，你不能在label.text中使用它，因为它是以Date格式存在的。你需要将这个Date转换成String，或者像这样使用：label.text = "\(getDate)"。试试这个方法。 - Naresh
29

Swift 3.0 - 4.2

import Foundation

extension String {

    func toDate(withFormat format: String = "yyyy-MM-dd HH:mm:ss")-> Date?{

        let dateFormatter = DateFormatter()
        dateFormatter.timeZone = TimeZone(identifier: "Asia/Tehran")
        dateFormatter.locale = Locale(identifier: "fa-IR")
        dateFormatter.calendar = Calendar(identifier: .gregorian)
        dateFormatter.dateFormat = format
        let date = dateFormatter.date(from: self)

        return date

    }
}

extension Date {

    func toString(withFormat format: String = "EEEE ، d MMMM yyyy") -> String {

        let dateFormatter = DateFormatter()
        dateFormatter.locale = Locale(identifier: "fa-IR")
        dateFormatter.timeZone = TimeZone(identifier: "Asia/Tehran")
        dateFormatter.calendar = Calendar(identifier: .persian)
        dateFormatter.dateFormat = format
        let str = dateFormatter.string(from: self)

        return str
    }
}
20
创建全局函数
func convertDateFormat(inputDate: String) -> String {

     let olDateFormatter = DateFormatter()
     olDateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"

     let oldDate = olDateFormatter.date(from: inputDate)

     let convertDateFormatter = DateFormatter()
     convertDateFormatter.dateFormat = "MMM dd yyyy h:mm a"

     return convertDateFormatter.string(from: oldDate!)
}

调用函数并传递参数

get_OutputStr = convertDateFormat(inputDate: "2019-03-30T05:30:00+0000")

这里是输出结果

Feb 25 2020 4:51 PM
7
你认为你的输入和输出是一样的吗？ - Deepak Carpenter
18

使用字符串扩展将字符串转换为日期的Swift代码 - 版本5.0

    extension String {
         public enum DateFormatType {
        
        /// The ISO8601 formatted year "yyyy" i.e. 1997
        case isoYear
        
        /// The ISO8601 formatted year and month "yyyy-MM" i.e. 1997-07
        case isoYearMonth
        
        /// The ISO8601 formatted date "yyyy-MM-dd" i.e. 1997-07-16
        case isoDate
        
        /// The ISO8601 formatted date and time "yyyy-MM-dd'T'HH:mmZ" i.e. 1997-07-16T19:20+01:00
        case isoDateTime
        
        /// The ISO8601 formatted date, time and sec "yyyy-MM-dd'T'HH:mm:ssZ" i.e. 1997-07-16T19:20:30+01:00
        case isoDateTimeSec
        
        /// The ISO8601 formatted date, time and millisec "yyyy-MM-dd'T'HH:mm:ss.SSSZ" i.e. 1997-07-16T19:20:30.45+01:00
        case isoDateTimeMilliSec
        
        /// The dotNet formatted date "/Date(%d%d)/" i.e. "/Date(1268123281843)/"
        case dotNet
        
        /// The RSS formatted date "EEE, d MMM yyyy HH:mm:ss ZZZ" i.e. "Fri, 09 Sep 2011 15:26:08 +0200"
        case rss
        
        /// The Alternative RSS formatted date "d MMM yyyy HH:mm:ss ZZZ" i.e. "09 Sep 2011 15:26:08 +0200"
        case altRSS
        
        /// The http header formatted date "EEE, dd MM yyyy HH:mm:ss ZZZ" i.e. "Tue, 15 Nov 1994 12:45:26 GMT"
        case httpHeader
        
        /// A generic standard format date i.e. "EEE MMM dd HH:mm:ss Z yyyy"
        case standard
        
        /// A custom date format string
        case custom(String)
        
        /// The local formatted date and time "yyyy-MM-dd HH:mm:ss" i.e. 1997-07-16 19:20:00
        case localDateTimeSec
        
        /// The local formatted date  "yyyy-MM-dd" i.e. 1997-07-16
        case localDate
        
        /// The local formatted  time "hh:mm a" i.e. 07:20 am
        case localTimeWithNoon
        
        /// The local formatted date and time "yyyyMMddHHmmss" i.e. 19970716192000
        case localPhotoSave
        
        case birthDateFormatOne
        
        case birthDateFormatTwo
        
        ///
        case messageRTetriveFormat
        
        ///
        case emailTimePreview
        
        var stringFormat:String {
          switch self {
          //handle iso Time
          case .birthDateFormatOne: return "dd/MM/YYYY"
          case .birthDateFormatTwo: return "dd-MM-YYYY"
          case .isoYear: return "yyyy"
          case .isoYearMonth: return "yyyy-MM"
          case .isoDate: return "yyyy-MM-dd"
          case .isoDateTime: return "yyyy-MM-dd'T'HH:mmZ"
          case .isoDateTimeSec: return "yyyy-MM-dd'T'HH:mm:ssZ"
          case .isoDateTimeMilliSec: return "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
          case .dotNet: return "/Date(%d%f)/"
          case .rss: return "EEE, d MMM yyyy HH:mm:ss ZZZ"
          case .altRSS: return "d MMM yyyy HH:mm:ss ZZZ"
          case .httpHeader: return "EEE, dd MM yyyy HH:mm:ss ZZZ"
          case .standard: return "EEE MMM dd HH:mm:ss Z yyyy"
          case .custom(let customFormat): return customFormat
            
          //handle local Time
          case .localDateTimeSec: return "yyyy-MM-dd HH:mm:ss"
          case .localTimeWithNoon: return "hh:mm a"
          case .localDate: return "yyyy-MM-dd"
          case .localPhotoSave: return "yyyyMMddHHmmss"
          case .messageRTetriveFormat: return "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
          case .emailTimePreview: return "dd MMM yyyy, h:mm a"
          }
        }  
 }
        
 func toDate(_ format: DateFormatType = .isoDate) -> Date?{
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = format.stringFormat
        let date = dateFormatter.date(from: self)
        return date 
  }
 }

我们使用类似于的方法。
    string.toDate(.isoDate)
    "1997-05-24".toDate(.isoDate)
17

Swift 5. 要查看日期是否已过期:

let expiryDate = "2020-01-10" // Jan 10 2020

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"

if Date() < dateFormatter.date(from: expiryDate) ?? Date() {
    print("Not Yet expiryDate")
} else {
    print("expiryDate has passed")
}
13
自 iOS 15.0 开始，我们可以以更加简洁的方式将字符串转换为日期：
let strategy = Date.ParseStrategy(format: "\(year: .defaultDigits)-\(month: .twoDigits)-\(day: .twoDigits)T\(hour: .twoDigits(clock: .twentyFourHour, hourCycle: .zeroBased)):\(minute: .twoDigits):\(second: .twoDigits)\(timeZone: .iso8601(.short))", timeZone: .current)
let date = try? Date("2016-04-14T10:44:00+0000", strategy: strategy)
12

您好，您可以先使用T格式进行分离，然后根据需要进行转换。

// create dateFormatter with UTC time format
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
dateFormatter.timeZone = NSTimeZone(name: "UTC")
let date = dateFormatter.dateFromString("2015-04-01T11:42:00")

// change to a readable time format and change to local time zone
dateFormatter.dateFormat = "EEE, MMM d, yyyy - h:mm a"
dateFormatter.timeZone = NSTimeZone.localTimeZone() 
let timeStamp = dateFormatter.stringFromDate(date!)
6

只需要传入您的dateformate和日期，您就可以得到年、月、日、小时。更多信息

func GetOnlyDateMonthYearFromFullDate(currentDateFormate:NSString , conVertFormate:NSString , convertDate:NSString ) -> NSString
    {
        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = currentDateFormate as String
        let formatter = NSDateFormatter()
        formatter.dateFormat = Key_DATE_FORMATE as String
        let finalDate = formatter.dateFromString(convertDate as String)
        formatter.dateFormat = conVertFormate as String
        let dateString = formatter.stringFromDate(finalDate!)

        return dateString
    }


获取年份

let Year = self.GetOnlyDateMonthYearFromFullDate("yyyy-MM-dd'T'HH:mm:ssZ", conVertFormate: "YYYY", convertDate: "2016-04-14T10:44:00+0000") as String


获取月份

let month = self.GetOnlyDateMonthYearFromFullDate("yyyy-MM-dd'T'HH:mm:ssZ", conVertFormate: "MM", convertDate: "2016-04-14T10:44:00+0000") as String


获取日期

let day = self.GetOnlyDateMonthYearFromFullDate("yyyy-MM-dd'T'HH:mm:ssZ", conVertFormate: "dd", convertDate: "2016-04-14T10:44:00+0000") as String


获取小时数

let hour  = self.GetOnlyDateMonthYearFromFullDate("yyyy-MM-dd'T'HH:mm:ssZ", conVertFormate: "hh", convertDate: "2016-04-14T10:44:00+0000") as String
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