将date和时间组合成单个NSDate的问题
我想结合一个NSDate的时间值（小时，分钟，秒）与第二个NSDate的date值（日，月，年）与此方法：
+ (NSDate *)combineDate:(NSDate *)date withTime:(NSDate *)time { NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDateComponents *dateComponents = [gregorian components:(NSDayCalendarUnit | NSWeekdayCalendarUnit) fromDate:date]; NSDateComponents *timeComponents = [gregorian components:(NSDayCalendarUnit | NSWeekdayCalendarUnit) fromDate:time]; NSDateComponents *comp = [NSDateComponents alloc]; [comp setSecond:[timeComponents second]]; [comp setHour:[timeComponents hour]]; [comp setMinute:[timeComponents minute]]; [comp setYear:[dateComponents year]]; [comp setMonth:[dateComponents month]]; [comp setDay:[dateComponents day]]; NSDate *combDate = [gregorian dateFromComponents:comp]; [gregorian release]; [comp release]; return combDate; }
…但它返回的实际上是乱码（例如，年份为“1”）。 有人看到这个方法有什么问题吗？
我正在使用错误的日历组件。 这里是更正后的function（现在是ARC）：
+ (NSDate *)combineDate:(NSDate *)date withTime:(NSDate *)time { NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier: NSGregorianCalendar]; unsigned unitFlagsDate = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit; NSDateComponents *dateComponents = [gregorian components:unitFlagsDate fromDate:date]; unsigned unitFlagsTime = NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit; NSDateComponents *timeComponents = [gregorian components:unitFlagsTime fromDate:time]; [dateComponents setSecond:[timeComponents second]]; [dateComponents setHour:[timeComponents hour]]; [dateComponents setMinute:[timeComponents minute]]; NSDate *combDate = [gregorian dateFromComponents:dateComponents]; return combDate; }
这是在Swift 2中
func combineDateAndTime(date: NSDate, time: NSDate) -> NSDate { let calendar = NSCalendar.currentCalendar() let dateComponents = calendar.components([.Year, .Month, .Day], fromDate: date) let timeComponents = calendar.components([.Hour, .Minute, .Second], fromDate: time) let components = NSDateComponents() components.year = dateComponents.year components.month = dateComponents.month components.day = dateComponents.day components.hour = timeComponents.hour components.minute = timeComponents.minute components.second = timeComponents.second return calendar.dateFromComponents(components)! }
斯威夫特3延伸：
func combineDateAndTime(date: Date, time: Date) -> Date { let calendar = NSCalendar.current let dateComponents = calendar.dateComponents([.year, .month, .day], from: date) let timeComponents = calendar.dateComponents([.hour, .minute, .second], from: time) var components = DateComponents() components.year = dateComponents.year components.month = dateComponents.month components.day = dateComponents.day components.hour = timeComponents.hour components.minute = timeComponents.minute components.second = timeComponents.second return calendar.date(from: components)! }
（Swift +扩展名）是你的朋友：
// MARK: - NSDate extension - extension NSDate { static func combineDate(date date: NSDate, withTime time: NSDate) -> NSDate? { let gregorian = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian) let dateComponents = gregorian?.components([.Year, .Month, .Day], fromDate: date) let timeComponents = gregorian?.components([.Hour, .Minute, .Second], fromDate: date) dateComponents?.second = timeComponents?.second ?? 0 dateComponents?.minute = timeComponents?.minute ?? 0 dateComponents?.hour = timeComponents?.hour ?? 0 if let _ = dateComponents { return gregorian?.dateFromComponents(dateComponents!) } return nil } }