从特定年份的周数获得dats

Question

我需要一个函数，我将传递任何周数和年份，该函数应返回该周的日期。就像我通过第2周和第2016年那样功能应该让我在1月3日到1月9日。

Answer 1

使用NSCalendar功能只是一个非常简单的解决方案：

let week = NSDateComponents()
week.yearForWeekOfYear = 2016 // the year
week.weekOfYear = 10 // week index

let calendar = NSCalendar.currentCalendar()

// start of week or nil if the week does not exist
let weekStart = calendar.dateFromComponents(week) 

// add 1 week to start (this is essentially the start of the next week)
let weekEnd = calendar.dateByAddingUnit(.WeekOfYear, value: 1, toDate: weekStart!, options: [])

print(weekStart)
print(weekEnd)