从[NSDate日期]获取当前日期,但将时间设置为上午10:00

Question

如何重置从[NSDate date]检索的当前日期,然后将时间更改为早上10:00.

Answer 1

与所有日期操作一样,您必须使用NSDateComponents和NSCalendar

NSDate *now = [NSDate date];
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier: NSCalendarIdentifierGregorian];
NSDateComponents *components = [calendar components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay fromDate:now];
[components setHour:10];
NSDate *today10am = [calendar dateFromComponents:components];

在iOS8中,Apple推出了一种方便的方法,可以节省几行代码:

NSDate *d = [calendar dateBySettingHour:10 minute:0 second:0 ofDate:[NSDate date] options:0];

迅速:

let calendar: NSCalendar! = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
let now: NSDate! = NSDate()

let date10h = calendar.dateBySettingHour(10, minute: 0, second: 0, ofDate: now, options: NSCalendarOptions.MatchFirst)!