你好,我想从当前日期减去天数、月份或一年。 我可以使用下面的代码创建一个距离当前日期一周后的日期。
let date = Date().addingTimeInterval(TimeInterval(86400*7))
如何创建一个比当前日期早一周的日期?
你好,我想从当前日期减去天数、月份或一年。 我可以使用下面的代码创建一个距离当前日期一周后的日期。
let date = Date().addingTimeInterval(TimeInterval(86400*7))
如何创建一个比当前日期早一周的日期?
Calendar
来进行这些计算,而不是硬编码每天的 86400
秒。if let date = Calendar.current.date(byAdding: .day, value: -7, to: Date()) {
// Use this date
}
Swift 5
用于在当前日期上加减天、月、年的函数。
func addOrSubtractDay(day:Int)->Date{
return Calendar.current.date(byAdding: .day, value: day, to: Date())!
}
func addOrSubtractMonth(month:Int)->Date{
return Calendar.current.date(byAdding: .month, value: month, to: Date())!
}
func addOrSubtractYear(year:Int)->Date{
return Calendar.current.date(byAdding: .year, value: year, to: Date())!
}
//Subtracting
var daySubtractedDate = addOrSubtractDay(-7)
var monthSubtractedDate = addOrSubtractMonth(-7)
var yearSubtractedDate = addOrSubtractYear(-7)
//Adding
var dayAddedDate = addOrSubtractDay(7)
var monthAddedDate = addOrSubtractMonth(7)
var yearAddedDate = addOrSubtractYear(7)
extension Date {
func get(_ components: Calendar.Component..., calendar: Calendar = Calendar.current) -> DateComponents {
return calendar.dateComponents(Set(components), from: self)
}
func get(_ component: Calendar.Component, calendar: Calendar = Calendar.current) -> Int {
return calendar.component(component, from: self)
}
}
使用以下方式使用扩展:
let date = Date()
let components = date.get(.day, .month, .year)
if let day = components.day, let month = components.month, let year = components.year {
print("day: \(day), month: \(month), year: \(year)")
}
获取上周日期,与今天精确对应
let lastWeekDate = Calendar.current.date(byAdding: .weekOfYear, value: -1, to: Date())!