比较三个日期答案

【问题标题】：Compare three dates比较三个日期
【发布时间】：2015-10-14 20:28:45
【问题描述】：

我有三个日期“startDate”，stopDate 和 currentDate。我需要比较 'startDate' = 'currentDate'。我的代码。

unsigned int flagsDate = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;

    NSDateComponents* fromComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:startDate];
    NSDate* fromDateOnly = [[NSCalendar currentCalendar] dateFromComponents:fromComponents];

    NSDateComponents* toComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:stopDate];
    NSDate* toDateOnly = [[NSCalendar currentCalendar] dateFromComponents:toComponents];

    NSDate * currentDate = [NSDate date];
    NSDateComponents* currComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate: currentDate];
    NSDate* currDateOnly = [[NSCalendar currentCalendar] dateFromComponents:currComponents];

    NSTimeInterval fromTime = [fromDateOnly timeIntervalSinceReferenceDate];
    NSTimeInterval toTime = [toDateOnly timeIntervalSinceReferenceDate];
    NSTimeInterval currTime = [currDateOnly timeIntervalSinceReferenceDate];

    NSLog(@"%@ %@",currentDate, currDateOnly);
    NSLog(@"%@ %@",startDate, fromDateOnly);
    NSLog(@"%@ %@",stopDate, toDateOnly);

这就是带来 nslog 的原因。

2014-04-10 23:59:53.280 日历[2148:90b] 2014-04-10 19:59:53 +0000 2014-04-09 20:00:00 +0000 2014-04-10 23:59:53.282 日历[2148:90b] 2014-04-10 20:14:12 +0000 2014-04-10 20:00:00 +0000 2014-04-10 23:59:53.282 日历[2148:90b] 2015-04-09 20:14:12 +0000 2015-04-09 20:00:00 +0000

如何比较日期？我只需要比较没有时间的日期。如果时间小于 20:00，为什么要更改日期？

【问题讨论】：

你不能指定你使用什么语言吗？

标签： objective-c nsdate

【解决方案1】：

NSTimeInterval distanceBetweenDates = [StartDate timeIntervalSinceDate:EndDate];

if (distanceBetweenDates > 0) {
    NSLog("Greather than ")
} else  if (distanceBetweenDates < 0) {
    NSLog("less than");
} else {
    NSLog("Equal");
}

【讨论】：

【解决方案2】：

Alexey，我建议你在你的项目中加入这个很棒的 NSDate 扩展：https://github.com/erica/NSDate-Extensions

然后你可以使用

- (NSInteger)distanceInDaysToDate:(NSDate *)anotherDate

并检查它是 0

【讨论】：

【解决方案3】：

如果您只想比较日期，请执行以下操作：

NSInteger flagsDate = (NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit);

NSDateComponents* fromComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:startDate];
NSDateComponents* toComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:stopDate];
NSDateComponents* currComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:cu];

NSComparisonResult firstComparison = [[fromComponents date] compare: [currComponents date]]; 
NSComparisonResult secondComparison = [[toComponents date] compare: [currComponents date]];

然后检查你的结果

if (firstComparison == NSOrderedDescending || firstComparison == NSOrderedSame) {}
if (secondComparison == NSOrderedSame || secondComparison == NSOrderedAscending) {}

【讨论】：