迭代一年以获取 Swift 中的每一天 NSDate 对象

Question

您好，我有一个方法可以返回每天的时间数组。

prayTimesDate(date: NSDate, latitide : Double, longitude : Double, timeZone : Double) -> NSMutableArray

我需要遍历一整年或一个日期范围，以获得一整年中每一天的时间数组。我在 ruby​​ 和 python 中找到了很多关于如何做到这一点的参考资料，但我找不到 swift 或 Objective-c 的任何东西。 swift中有没有内置的方法可以实现这一点？如果没有，有人可以帮助我，因为我还是编程新手。非常感谢任何输入。

这是我链接到我的 swift 项目的方法的 Objective-c 代码

- (NSMutableArray *)prayerTimesDate:(NSDate *)date latitude:(double)latitude longitude:(double)longitude andTimezone:(double)timezone
{
    unsigned unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth |  NSCalendarUnitDay;
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *components = [calendar components:unitFlags fromDate:date];

    NSInteger year = [components year];
    NSInteger month = [components month];
    NSInteger day = [components day];

    return [self getDatePrayerTimesForYear:year month:month day:day latitude:latitude longitude:longitude andtimeZone:timezone];
}

Answer 1

假设您的 prayerTimesDate: 方法已经返回了预期的结果，您可以在一年中的每一天循环，同时反复调用 prayerTimesDate: 以获取包含每天祈祷时间的数组，例如：

func yearlyPrayerDatesFromCurrentDate (latitude:Double, longitude:Double, timezone:Double) -> NSMutableArray {

    // Set "date" to equal the current day
    var date:NSDate! = NSDate()

    // Increment "date" by one year to calculate the ending
    // date for the loop
    let gregorian:NSCalendar! = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
    let dateComponents = NSDateComponents()
    dateComponents.year = 1
    let endingDate:NSDate! = gregorian.dateByAddingComponents(dateComponents, toDate: date, options: nil)

    // Create an array to hold *all* the returned 
    // results for the year
    var datesArray = NSMutableArray()

    // Loop through each date until the ending date is
    // reached
    while date.compare(endingDate) != NSComparisonResult.OrderedDescending {
        // Call your prayerTimesDate: method on the current
        // date to get that date's prayer times and add the
        // times from the returned array to the datesArray
        datesArray.addObjectsFromArray(prayerTimesDate(date, latitude: latitude, longitude: longitude, andTimezone: timezone))

        // increment the date by 1 day
        let dateComponents = NSDateComponents()
        dateComponents.day = 1
        date = gregorian.dateByAddingComponents(dateComponents, toDate: date, options: nil)
    }

    return datesArray
}

Answer 2

这是超过 14 天的另一个示例（没有 NSCalendar）：

let ti:NSTimeInterval = 24*60*60 //one day
let dateFrom = NSDate() //Now
let dateTo = dateFrom.dateByAddingTimeInterval(24*60*60*14) //14 Days later

var nextDate = NSDate()
var endDate = dateTo.dateByAddingTimeInterval(ti)

while nextDate.compare(endDate) == NSComparisonResult.OrderedAscending
{      
    print("nextDate:", nextDate)
    nextDate = nextDate.dateByAddingTimeInterval(ti)
}

Answer 3

为 1 天创建一个 NSDateComponents 实例，在第一天的每个时间创建一个 NSDate 对象。现在您可以遍历您想要的天数（或直到您点击结束日期），然后您可以使用日历的dateByAddingComponents:toDate:options: 来获取每一天的新日期。

Answer 4

来自 Apple 文档：要计算日期序列，请使用 enumerateDatesStartingAfterDate:matchingComponents:options:usingBlock: 方法，而不是在具有前一个循环迭代结果的循环中调用此方法 ( - nextDateAfterDate:matchingComponents:options: )。

如我所见，它将迭代所有与“matchingComponents”匹配的日期，直到您使用“stop.memory = true”完成迭代

//: Playground - noun: a place where people can play

import UIKit

let calendar = NSCalendar.currentCalendar()
let startDate = calendar.startOfDayForDate(NSDate())
let finishDate = calendar.dateByAddingUnit(.Day, value: 10, toDate: startDate, options: [])
let dayComponent = NSDateComponents()
dayComponent.hour = 1

calendar.enumerateDatesStartingAfterDate(startDate, matchingComponents: dayComponent, options: [.MatchStrictly]) { (date, exactMatch, stop) in
    print(date)
    if date!.compare(finishDate!) == NSComparisonResult.OrderedDescending {
        // .memory gets at the value of an UnsafeMutablePointer
        stop.memory = true
    }
}