NSDate的NSDateComponents

Question

如何獲取單個NSDate的NSDateComponents？我不想要兩個日期之間的差異組件，只是NSDate的秒，分，小時，日，月和年？

Answer 1

這裏有一個例子在Apple docs，清單3：獲取日期的組件：

NSDate *today = [NSDate date]; 
NSCalendar *gregorian = [[NSCalendar alloc] 
         initWithCalendarIdentifier:NSGregorianCalendar]; 
NSDateComponents *weekdayComponents = 
        [gregorian components:(NSDayCalendarUnit | 
              NSWeekdayCalendarUnit) fromDate:today]; 
NSInteger day = [weekdayComponents day]; 
NSInteger weekday = [weekdayComponents weekday]; 

請注意，你必須「或」在一起calendar units要在components方法的調用。

Answer 2

使用NSCalendar的方法：

- (NSDateComponents *)components:(NSUInteger)unitFlags fromDate:(NSDate *)date

，如：

unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit; 
NSDate *date = [NSDate date]; 


NSCalendar * cal = [NSCalendar currentCalendar]; 
NSDateComponents *comps = [cal components:unitFlags fromDate:date]; 

Answer 3

斯威夫特

2.X你想要的成分被送到這個樣子。

let gregorianCalendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian) 
let weekdayHourMinutes = gregorianCalendar?.components([.Weekday, .Hour, .Minute], fromDate: date) 

Answer 4

根據蘋果開發者API參考，DateComponents有second，minute，hour，day，month，year實例屬性。

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以下斯威夫特3遊樂場代碼展示瞭如何使用DateComponents獲得從Date例如秒，分鐘，小時，天，月，年組件：

import Foundation 

var calendar = Calendar(identifier: .gregorian) 
calendar.timeZone = TimeZone(abbreviation: "CET")! 
let date = Date() 

// Get seconds, minutes, hours, day, month and year 
let components = calendar.dateComponents([.second, .minute, .hour, .day, .month, .year], from: date) 
let seconds = components.second 
let minutes = components.minute 
let hours = components.hour 
let day = components.day 
let month = components.month 
let year = components.year 

// Print components 
print(String(reflecting: seconds)) // prints Optional(33) 
print(String(reflecting: minutes)) // prints Optional(42) 
print(String(reflecting: hours)) // prints Optional(22) 
print(String(reflecting: day)) // prints Optional(17) 
print(String(reflecting: month)) // prints Optional(12) 
print(String(reflecting: year)) // prints Optional(2016) 

/* ... */ 

// Set a formatter in order to display date 
let formatter = DateFormatter() 
formatter.dateStyle = .short 
formatter.timeStyle = .long 
formatter.timeZone = TimeZone(abbreviation: "CET") 
formatter.locale = Locale(identifier: "fr_FR") 
print(formatter.string(from: date)) // prints 17/12/2016 22:42:33 UTC+1