我正在尝试获取本周星期一的日期。在我的表格视图中,这被视为一周的第一天。我还需要获取当前一周的星期日。在我的表格视图中,这被视为一周的最后一天。
当前尝试:
let date = NSDate() let calendar = NSCalendar.currentCalendar() calendar.firstWeekday = 1 //attempt to changefirstday let dateFormatter = NSDateFormatter() let theDateFormat = NSDateFormatterStyle.ShortStyle let theTimeFormat = NSDateFormatterStyle.ShortStyle dateFormatter.dateStyle = theDateFormat dateFormatter.timeStyle = theTimeFormat let currentDateComponents = calendar.components([.YearForWeekOfYear, .WeekOfYear ], fromDate: date) let startOfWeek = calendar.dateFromComponents(currentDateComponents) print("startOfWeek is \(startOfWeek)") let stringDate = dateFormatter.stringFromDate(startOfWeek!) print("string date is \(stringDate)") //This is returning Sunday's date
我写了Date扩展名以获取某个工作日的Date,这就是在Swift 5中使用它的简便性
Date.today() // Oct 15, 2019 at 9:21 AM Date.today().next(.monday) // Oct 21, 2019 at 9:21 AM Date.today().next(.sunday) // Oct 20, 2019 at 9:21 AM Date.today().previous(.sunday) // Oct 13, 2019 at 9:21 AM Date.today().previous(.monday) // Oct 14, 2019 at 9:21 AM Date.today().previous(.thursday) // Oct 10, 2019 at 9:21 AM Date.today().next(.thursday) // Oct 17, 2019 at 9:21 AM Date.today().previous(.thursday, considerToday: true) // Oct 10, 2019 at 9:21 AM Date.today().next(.monday) .next(.sunday) .next(.thursday) // Oct 31, 2019 at 9:21 AM
这是日期扩展,
extension Date { static func today() -> Date { return Date() } func next(_ weekday: Weekday, considerToday: Bool = false) -> Date { return get(.next, weekday, considerToday: considerToday) } func previous(_ weekday: Weekday, considerToday: Bool = false) -> Date { return get(.previous, weekday, considerToday: considerToday) } func get(_ direction: SearchDirection, _ weekDay: Weekday, considerToday consider: Bool = false) -> Date { let dayName = weekDay.rawValue let weekdaysName = getWeekDaysInEnglish().map { $0.lowercased() } assert(weekdaysName.contains(dayName), "weekday symbol should be in form \(weekdaysName)") let searchWeekdayIndex = weekdaysName.firstIndex(of: dayName)! + 1 let calendar = Calendar(identifier: .gregorian) if consider && calendar.component(.weekday, from: self) == searchWeekdayIndex { return self } var nextDateComponent = calendar.dateComponents([.hour, .minute, .second], from: self) nextDateComponent.weekday = searchWeekdayIndex let date = calendar.nextDate(after: self, matching: nextDateComponent, matchingPolicy: .nextTime, direction: direction.calendarSearchDirection) return date! } } // MARK: Helper methods extension Date { func getWeekDaysInEnglish() -> [String] { var calendar = Calendar(identifier: .gregorian) calendar.locale = Locale(identifier: "en_US_POSIX") return calendar.weekdaySymbols } enum Weekday: String { case monday, tuesday, wednesday, thursday, friday, saturday, sunday } enum SearchDirection { case next case previous var calendarSearchDirection: Calendar.SearchDirection { switch self { case .next: return .forward case .previous: return .backward } } } }