在下面的图片中，您可以看到我编写的代码和所有变量的值：
class fun getCurrentShortDate() -> String {
var todaysDate = NSDate()
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy"
var DateInFormat = dateFormatter.stringFromDate(todaysDate)
return DateInFormat
}
正如您所看到的那样，当前日期没有问题，但是当我尝试将NSDate更改为字符串时，它就不会这样做了。
Xcode 8或更高版本•Swift 3或更高版本
extension Date {
func localizedDescription(dateStyle: DateFormatter.Style = .medium,
timeStyle: DateFormatter.Style = .medium,
in timeZone : TimeZone = .current,
locale : Locale = .current) -> String {
Formatter.date.locale = locale
Formatter.date.timeZone = timeZone
Formatter.date.dateStyle = dateStyle
Formatter.date.timeStyle = timeStyle
return Formatter.date.string(from: self)
}
var localizedDescription: String { return localizedDescription() }
}
extension TimeZone {
static let gmt = TimeZone(secondsFromGMT: 0)!
}
extension Formatter {
static let date = DateFormatter()
}
Date().localizedDescription // "Sep 26, 2018 at 12:03:41 PM"
Date().localizedDescription(in: .gmt) // "Sep 26, 2018 at 3:03:41 PM" UTC TIME
Date().localizedDescription(dateStyle: .short, timeStyle: .short) // "9/26/18, 12:03 PM"
Date().localizedDescription(dateStyle: .full, timeStyle: .full) // "Wednesday, September 26, 2018 at 12:03:41 PM Brasilia Standard Time"
Date().localizedDescription(dateStyle: .full, timeStyle: .full, in: .gmt) // "Wednesday, September 26, 2018 at 3:03:41 PM Greenwich Mean Time"
extension Date {
var fullDate: String { return localizedDescription(dateStyle: .full, timeStyle: .none) }
var shortDate: String { return localizedDescription(dateStyle: .short, timeStyle: .none) }
var fullTime: String { return localizedDescription(dateStyle: .none, timeStyle: .full) }
var shortTime: String { return localizedDescription(dateStyle: .none, timeStyle: .short) }
var fullDateTime: String { return localizedDescription(dateStyle: .full, timeStyle: .full) }
var shortDateTime: String { return localizedDescription(dateStyle: .short, timeStyle: .short) }
}
print(Date().fullDate) // "Friday, May 26, 2017\n"
print(Date().shortDate) // "5/26/17\n"
print(Date().fullTime) // "10:16:24 AM Brasilia Standard Time\n"
print(Date().shortTime) // "10:16 AM\n"
print(Date().fullDateTime) // "Friday, May 26, 2017 at 10:16:24 AM Brasilia Standard Time\n"
print(Date().shortDateTime) // "5/26/17, 10:16 AM\n"
更新Swift 3.0：为Date创建扩展
extension Date {
func string(format: String) -> String {
let formatter = DateFormatter()
formatter.dateFormat = format
return formatter.string(from: self)
}
}
用法：
Date().string(format: "yyyy-MM-dd")
Swift 2.2：为NSDate创建扩展
extension NSDate {
func dateStringWithFormat(format: String) -> String {
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = format
return dateFormatter.stringFromDate(self)
}
}
用法：
NSDate().dateStringWithFormat("yyyy-MM-dd")
您可以创建一个扩展，以便轻松地将String转换为NSDate。
extension NSDate {
func dateFromString(date: String, format: String) -> NSDate {
let formatter = NSDateFormatter()
let locale = NSLocale(localeIdentifier: "en_US_POSIX")
formatter.locale = locale
formatter.dateFormat = format
return formatter.dateFromString(date)!
}
}
比你的功能，你可以NSDate().dateFromString("2015-02-04 23:29:28", format: "yyyy-MM-dd HH:mm:ss")，这应该工作。输入日期不需要与输出日期的格式相同。
func getCurrentShortDate() -> String {
var todaysDate = NSDate().dateFromString("2015-02-04 23:29:28", format: "yyyy-MM-dd HH:mm:ss")
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy"
var DateInFormat = dateFormatter.stringFromDate(todaysDate)
return DateInFormat
}
println(getCurrentShortDate())
输出是04-02-2015。
斯威夫特3
使用@doovers创建的扩展和来自此website的一些格式字符串，您将获得以下内容：
extension Date {
func string(format: String) -> String {
let formatter = DateFormatter()
formatter.dateFormat = format
return formatter.string(from: self)
}
}
用法：
Date().string(format: "EEEE, MMM d, yyyy") // Saturday, Oct 21, 2017
Date().string(format: "MM/dd/yyyy") // 10/21/2017
Date().string(format: "MM-dd-yyyy HH:mm") // 10-21-2017 03:31
Date().string(format: "MMM d, h:mm a") // Oct 21, 3:31 AM
Date().string(format: "MMMM yyyy") // October 2017
Date().string(format: "MMM d, yyyy") // Oct 21, 2017
Date().string(format: "E, d MMM yyyy HH:mm:ss Z") // Sat, 21 Oct 2017 03:31:40 +0000
Date().string(format: "yyyy-MM-dd'T'HH:mm:ssZ") // 2017-10-21T03:31:40+0000
Date().string(format: "dd.MM.yy") // 21.10.17
您还可以将毫秒传递给日期对象，如下所示：
Date(1508577868947).string(format: "EEEE, MMM d, yyyy") // Saturday, Oct 21, 2017
这是Apple建议的方式
let formatter = DateFormatter()
formatter.locale = Locale.current
formatter.dateStyle = .short
let dateString = formatter.string(from: date)
或者，如果.short，.medium，.long和.full的预定义格式非常正确，请在区域设置中创建模板
let formatter = DateFormatter()
formatter.locale = Locale.current
formatter.setLocalizedDateFormatFromTemplate("MM/dd/yyyy")
let dateString = formatter.string(from: date)
这是link
SWIFT 4或5
extension Date {
static func getCurrentDate() -> String {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd/MM/yyyy HH:mm:ss"
return dateFormatter.string(from: Date())
}
}
运用
print(Date.getCurrentDate())
let dateformatter1 = DateFormatter()
dateformatter1.dateFormat = "ccc, d MMM yyy"
let dateString1 = dateformatter1.string(from: datePicker.date)
print("Date Selected \(dateString1)")
labelDate.text = dateString1
let dateformatter2 = DateFormatter()
dateformatter2.dateFormat = "dd-MM-yyyy"
let dateString2 = dateformatter2.string(from: datePicker.date)
print("Date Selected \(dateString2)")
let dateformatter3 = DateFormatter()
dateformatter3.dateFormat = "dd/MM/yyyy"
let dateString3 = dateformatter3.string(from: datePicker.date)
print("Date Selected \(dateString3)")
let dateformatter4 = DateFormatter()
dateformatter4.dateFormat = "dd MMMM yyyy hh:mm a"
let dateString4 = dateformatter4.string(from: datePicker.date)
print("Date Selected \(dateString4)")
我在Codzify.com上提到了这篇文章。真有帮助。