检查两个日期是否相隔一个月

Question

我正在尝试检查两个日期是否相隔 1 个月。我读到我应该使用 NSCalendar

中的这种方法 components:fromDate:toDate:options:

我的代码

#define FORMAT_DATE_TIME @"dd-MM-yyyy HH:mm"

NSDate *updateDate = [Utils getDateFromString:airport.updateOn withFormat:FORMAT_DATE_TIME];
NSDate *now = [NSDate date];
NSString *nowString = [Utils getStringFromDate:now withFormat:FORMAT_DATE_TIME];
now = [Utils getDateFromString:nowString withFormat:FORMAT_DATE_TIME];

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
NSDateComponents *comps = [calendar components:NSCalendarUnitMonth fromDate:updateDate toDate:now options:0];

NSLog(@"%ld", (long)[comps year]);
NSLog(@"%ld", (long)[comps month]);
NSLog(@"%ld", (long)[comps day]);

这些是日志：

(lldb) Year: 9223372036854775807

(lldb) Month: 0

(lldb) Day: 9223372036854775807

(lldb) po now 2017-08-23 11:54:00 +0000

(lldb) po updateDate 2017-08-23 11:48:00 +0000

不应该所有的值都为零吗？

Answer 1

下一行不包括年（NSCalendarUnitYear）和日（NSCalendarUnitDay）部分，只包括月（NSCalendarUnitMonth）部分。

NSDateComponents *components = [calendar components:NSCalendarUnitMonth fromDate:updateDate toDate:now options:0];

添加 NSCalendarUnitYear 和 NSCalendarUnitDay 得到 [comps year] & [comps day] 为 0。

像这样：

NSDateComponents * components = [calendar components:NSCalendarUnitMonth |NSCalendarUnitYear|NSCalendarUnitDay fromDate:updateDate toDate:now options:0];

Answer 2

你可以使用这个

 NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:FORMAT_DATE_TIME];
NSDate *updateDate  = [dateFormatter dateFromString:@"24-07-1990 15:20"];

NSDate *now = [NSDate date];


NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];

unsigned unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth |  NSCalendarUnitDay;


NSDateComponents *comps = [calendar components:unitFlags fromDate:updateDate toDate:now options:0];


NSLog(@"%ld", (long)[comps year]);
NSLog(@"%ld", (long)[comps month]);
NSLog(@"%ld", (long)[comps day]);

检查两个日期是否相隔一个月

Check if two dates are one month apart

objective-c

nsdate

nscalendar

nsdatecomponents