如何快速地获得当周的星期一的日期 [英] How to get Monday's date of the current week in swift

问题描述

我正在尝试星期一的当天的日期。这在我的表格视图中被视为一周的第一天。
我也需要得到本周的星期日。这被视为我的表格视图中的最后一天。

I'm trying to get Monday's date of the current week. This is treated as the first day of the week in my table view. I also need to get Sunday's of the current week. This is treated as the last day of the week in my table view.

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

推荐答案

这是一个简单的功能，将giv你本周的星期一的日期，

Here is a simple function that will give you this week's Monday's date,

func getWeekDaysInEnglish() -> [String] {
    let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)!
    calendar.locale = NSLocale(localeIdentifier: "en_US_POSIX")
    return calendar.weekdaySymbols
}

enum SearchDirection {
    case Next
    case Previous

    var calendarOptions: NSCalendarOptions {
        switch self {
            case .Next:
                return .MatchNextTime
            case .Previous:
                return [.SearchBackwards, .MatchNextTime]
        }
    }
}

func get(direction: SearchDirection, _ dayName: String, considerToday consider: Bool = false) -> NSDate {
    let weekdaysName = getWeekDaysInEnglish()

    assert(weekdaysName.contains(dayName), "weekday symbol should be in form \(weekdaysName)")

    let nextWeekDayIndex = weekdaysName.indexOf(dayName)! + 1 // weekday is in form 1 ... 7 where as index is 0 ... 6

    let today = NSDate()

    let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)!

    if consider && calendar.component(.Weekday, fromDate: today) == nextWeekDayIndex {
        return today
    }

    let nextDateComponent = NSDateComponents()
    nextDateComponent.weekday = nextWeekDayIndex


    let date = calendar.nextDateAfterDate(today, matchingComponents: nextDateComponent, options: direction.calendarOptions)
    return date!
}

get(.Next, "Monday") // Nov 2, 2015, 12:00 AM
get(.Next, "Sunday") // Nov 1, 2015, 12:00 AM

get(.Previous, "Sunday") // Oct 25, 2015, 12:00 AM
get(.Previous, "Monday") // Oct 26, 2015, 12:00 AM

get(.Previous, "Thursday") // Oct 22, 2015, 12:00 AM
get(.Next, "Thursday") // Nov 5, 2015, 12:00 AM
get(.Previous, "Thursday", considerToday:  true) // // Oct 29, 2015, 12:00 AM

您可以使用此方法获取您提供的任何日期和日期名称，这些功能应该是这些，

You can use this method to get any days and day name you provide to the function should be either of these,

"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"

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