objective-c - 通过组合两个 NSDate 来创建一个新的 NSDate

Question

我有 NSDate* day1 和 NSDate* day2。我如何通过只复制第 1 天的年/月/日和第 2 天的小时/分钟/秒来制作 NSDate* day3？

Answer 1

unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit;
NSDateComponents *comps = [[NSCalendar currentCalendar] components:unitFlags fromDate:day1];
NSDate *day3 = [[NSCalendar currentCalendar] dateFromComponents:comps];

unitFlags = NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
comps = [[NSCalendar currentCalendar] components:unitFlags fromDate:day2];
day3 = [[NSCalendar currentCalendar] dateByAddingComponents:comps toDate:day3 options:0];

来源:

1. NSDateComponents Class Reference
2. NSCalendar Class Reference