Question

我想在当前日期和时间后两天设置日期和时间。如何使用NSDate和dateformatter设置它。我希望在两天之后比较日期，它是否已经过去了。

我现在为它编写代码， NSCalendar * calendar = [NSCalendar autoupdatingCurrentCalendar];

NSDate *pickerDate = [self.datePicker date];

NSDateComponents *dateComponents = [calendar components:( NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit ) 
                                               fromDate:pickerDate];

NSDateComponents *timeComponents = [calendar components:( NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) 
                                               fromDate:pickerDate];

NSDateComponents *dateComps = [[NSDateComponents alloc] init];

[dateComps setDay:[dateComponents day]];
[dateComps setMonth:[dateComponents month]];
[dateComps setYear:[dateComponents year]];
[dateComps setHour:[timeComponents hour]];
[dateComps setMinute:[timeComponents minute]];
[dateComps setSecond:00];

NSDate *itemDate = [calendar dateFromComponents:dateComps];
[dateComps release];
appDelegate.setTimerByUser = [itemDate retain];

我如何将它与当前时间和日期进行比较？感谢

Answer 1

查看NSDate.h并阅读Apple的文档，了解NSDates上的-compare函数。

你可以这样做：

NSDate  *now = [NSDate date];
NSDate  *future = [now dateByAddingTimeInterval: 2 * 24 * 60 * 60]; // add two days

if ( [now compare: future] == NSOrderedAscending ) {
    // now is earlier than future so we will always get here
} else {
    // never reached but illustrates how you might use compare
}

Answer 2

我认为你需要NSDateComponents。您可以使用此类来获取有关日期和时间的年，月，日和其他属性。

Answer 3

NSDate * now = [NSDate date];
NSDate * twoDaysFromNow = [now dateByAddingTimeInterval:(2 * 24* 60 * 60)];

您可以与NSDate的-earlierDate:或-laterDate:方法进行比较。

我如何比较Iphone中的两个日期？

3 个答案: