对时间戳的判断（扩展）

在.h文件里面

#import@interface NSDate (Extension)

/**

*  判断某个时间是否为今年

*/

- (BOOL)isThisYear;

/**

*  判断某个时间是否为昨天

*/

- (BOOL)isYesterday;

/**

*  判断某个时间是否为今天

*/

- (BOOL)isToday;

@end

在.m文件中

#import "NSDate+Extension.h"

@implementation NSDate (Extension)

/**

*  判断某个时间是否为今年

*/

- (BOOL)isThisYear

{

NSCalendar *calendar = [NSCalendar currentCalendar];

// 获得某个时间的年月日时分秒

NSDateComponents *dateCmps = [calendar components:NSCalendarUnitYear fromDate:self];

NSDateComponents *nowCmps = [calendar components:NSCalendarUnitYear fromDate:[NSDate date]];

return dateCmps.year == nowCmps.year;

}

/**

*  判断某个时间是否为昨天

*/

- (BOOL)isYesterday

{

NSDate *now = [NSDate date];

// date ==  2014-04-30 10:05:28 --> 2014-04-30 00:00:00

// now == 2014-05-01 09:22:10 --> 2014-05-01 00:00:00

NSDateFormatter *fmt = [[NSDateFormatter alloc] init];

fmt.dateFormat = @"yyyy-MM-dd";

// 2014-04-30

NSString *dateStr = [fmt stringFromDate:self];

// 2014-10-18

NSString *nowStr = [fmt stringFromDate:now];

// 2014-10-30 00:00:00

NSDate *date = [fmt dateFromString:dateStr];

// 2014-10-18 00:00:00

now = [fmt dateFromString:nowStr];

NSCalendar *calendar = [NSCalendar currentCalendar];

NSCalendarUnit unit = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;

NSDateComponents *cmps = [calendar components:unit fromDate:date toDate:now options:0];

return cmps.year == 0 && cmps.month == 0 && cmps.day == 1;

}

/**

*  判断某个时间是否为今天

*/

- (BOOL)isToday

{

NSDate *now = [NSDate date];

NSDateFormatter *fmt = [[NSDateFormatter alloc] init];

fmt.dateFormat = @"yyyy-MM-dd";

NSString *dateStr = [fmt stringFromDate:self];

NSString *nowStr = [fmt stringFromDate:now];

return [dateStr isEqualToString:nowStr];

}

@end