我想要获得周一的本周日期。这在我的表格视图中被视为一周的第一天。我还需要获得本周的周日。在我的表视图中,这被视为一周的最后一天。
目前的尝试:
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
我写了日期扩展以获取特定工作日的日期,这里使用Swift 4是多么容易,
Date.today().next(.monday) // Feb 12, 2018 at 12:00 AM
Date.today().next(.sunday) // Feb 11, 2018 at 12:00 AM
Date.today().previous(.sunday) // Feb 4, 2018 at 12:00 AM
Date.today().previous(.monday) // Feb 5, 2018 at 12:00 AM
Date.today().previous(.thursday) // Feb 1, 2018 at 12:00 AM
Date.today().next(.thursday) // Feb 15, 2018 at 12:00 AM
Date.today().previous(.thursday,
considerToday: true) // Feb 8, 2018 at 11:04 PM
Date.today().next(.monday)
.next(.sunday)
.next(.thursday) // Feb 22, 2018 at 12:00 AM
这是Date扩展名,
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.index(of: dayName)! + 1
let calendar = Calendar(identifier: .gregorian)
if consider && calendar.component(.weekday, from: self) == searchWeekdayIndex {
return self
}
var nextDateComponent = DateComponents()
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
}
}
}
}
您可以使用日历ISO8601,其中第一个工作日是星期一:
Swift 3或更高版本
var mondaysDate: Date {
return Calendar(identifier: .iso8601).date(from: Calendar(identifier: .iso8601).dateComponents([.yearForWeekOfYear, .weekOfYear], from: Date()))!
}
print(mondaysDate.description(with: .current)) // Monday, July 16, 2018 at 12:00:00 AM Brasilia Standard Time"
作为扩展:
extension Calendar {
static let iso8601 = Calendar(identifier: .iso8601)
}
extension Date {
var currentWeekMonday: Date {
return Calendar.iso8601.date(from: Calendar.iso8601.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self))!
}
}
let currentWeekMonday = Date().currentWeekMonday
print(currentWeekMonday.description(with: .current)) // Monday, July 16, 2018 at 12:00:00 AM Brasilia Standard Time
这是我创建的扩展,首先它找到了星期天,然后它增加了一天
extension Date {
var startOfWeek: Date? {
let gregorian = Calendar(identifier: .gregorian)
guard let sunday = gregorian.date(from: gregorian.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self)) else { return nil }
return gregorian.date(byAdding: .day, value: 1, to: sunday)
}
}
这是Sandeep's answer的简化版本。
用法:
Date().next(.monday)
Date().next(.monday, considerToday: true)
Date().next(.monday, direction: .backward)
延期:
public func next(_ weekday: Weekday,
direction: Calendar.SearchDirection = .forward,
considerToday: Bool = false) -> Date
{
let calendar = Calendar(identifier: .gregorian)
let components = DateComponents(weekday: weekday.rawValue)
if considerToday &&
calendar.component(.weekday, from: self) == weekday.rawValue
{
return self
}
return calendar.nextDate(after: self,
matching: components,
matchingPolicy: .nextTime,
direction: direction)!
}
public enum Weekday: Int {
case sunday = 1, monday, tuesday, wednesday, thursday, friday, saturday
}
尝试使用:
calendar.firstWeekday = 2
编辑
更具体地说:NSCalendar.currentCalendar()
返回用户日历。根据文件:
返回的日历由当前用户选择的系统区域设置的设置形成,并覆盖用户在“系统偏好设置”中指定的任何自定义设置。
如果你想要星期一作为第一天,我认为你应该使用:
let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)!
calendar!.firstWeekday = 2
除了@Saneep回答
如果你想根据给定/当前日期获得确切的dateTime(假设你想将周一的dateTime - > 23-05-2016 12:00:00
转换为23-05-2016 05:35:17
),那么试试这个:
func convertDate(date: NSDate, toGivendate: NSDate) -> NSDate {
let calendar = NSCalendar.currentCalendar()
let comp = calendar.components([.Year, .Month, .Day, .Hour, .Minute, .Second], fromDate: toGivendate)
let hour = comp.hour
let minute = comp.minute
let second = comp.second
let dateComp = calendar.components([.Year, .Month, .Day], fromDate: date)
let year = dateComp.year
let month = dateComp.month
let day = dateComp.day
let components = NSDateComponents()
components.year = year
components.month = month
components.day = day
components.hour = hour
components.minute = minute
components.second = second
let newConvertedDate = calendar.dateFromComponents(components)
return newConvertedDate!
}
Swift 4解决方案
我根据我的要求想出了哪里,我找到了以下的日期。
1. Today
2. Tomorrow
3. This Week
4. This Weekend
5. Next Week
6. Next Weekend
所以,我创建了Date Extension
以获得当前周和下周的日期。
码
extension Date {
func getWeekDates() -> (thisWeek:[Date],nextWeek:[Date]) {
var tuple: (thisWeek:[Date],nextWeek:[Date])
var arrThisWeek: [Date] = []
for i in 0..<7 {
arrThisWeek.append(Calendar.current.date(byAdding: .day, value: i, to: startOfWeek)!)
}
var arrNextWeek: [Date] = []
for i in 1...7 {
arrNextWeek.append(Calendar.current.date(byAdding: .day, value: i, to: arrThisWeek.last!)!)
}
tuple = (thisWeek: arrThisWeek,nextWeek: arrNextWeek)
return tuple
}
var tomorrow: Date {
return Calendar.current.date(byAdding: .day, value: 1, to: noon)!
}
var noon: Date {
return Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: self)!
}
var startOfWeek: Date {
let gregorian = Calendar(identifier: .gregorian)
let sunday = gregorian.date(from: gregorian.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self))
return gregorian.date(byAdding: .day, value: 1, to: sunday!)!
}
func toDate(format: String) -> String {
let formatter = DateFormatter()
formatter.dateFormat = format
return formatter.string(from: self)
}
}
用法:
let arrWeekDates = Date().getWeekDates() // Get dates of Current and Next week.
let dateFormat = "MMM dd" // Date format
let thisMon = arrWeekDates.thisWeek.first!.toDate(format: dateFormat)
let thisSat = arrWeekDates.thisWeek[arrWeekDates.thisWeek.count - 2].toDate(format: dateFormat)
let thisSun = arrWeekDates.thisWeek[arrWeekDates.thisWeek.count - 1].toDate(format: dateFormat)
let nextMon = arrWeekDates.nextWeek.first!.toDate(format: dateFormat)
let nextSat = arrWeekDates.nextWeek[arrWeekDates.nextWeek.count - 2].toDate(format: dateFormat)
let nextSun = arrWeekDates.nextWeek[arrWeekDates.nextWeek.count - 1].toDate(format: dateFormat)
print("Today: \(Date().toDate(format: dateFormat))") // Sep 26
print("Tomorrow: \(Date().tomorrow.toDate(format: dateFormat))") // Sep 27
print("This Week: \(thisMon) - \(thisSun)") // Sep 24 - Sep 30
print("This Weekend: \(thisSat) - \(thisSun)") // Sep 29 - Sep 30
print("Next Week: \(nextMon) - \(nextSun)") // Oct 01 - Oct 07
print("Next Weekend: \(nextSat) - \(nextSun)") // Oct 06 - Oct 07
您可以根据需要修改Extension
。
谢谢!