在.h文件里面
#import@interface NSDate (Extension)
/**
*? 判斷某個時間是否為今年
*/
- (BOOL)isThisYear;
/**
*? 判斷某個時間是否為昨天
*/
- (BOOL)isYesterday;
/**
*? 判斷某個時間是否為今天
*/
- (BOOL)isToday;
@end
在.m文件中
#import "NSDate+Extension.h"
@implementation NSDate (Extension)
/**
*? 判斷某個時間是否為今年
*/
- (BOOL)isThisYear
{
NSCalendar *calendar = [NSCalendar currentCalendar];
// 獲得某個時間的年月日時分秒
NSDateComponents *dateCmps = [calendar components:NSCalendarUnitYear fromDate:self];
NSDateComponents *nowCmps = [calendar components:NSCalendarUnitYear fromDate:[NSDate date]];
return dateCmps.year == nowCmps.year;
}
/**
*? 判斷某個時間是否為昨天
*/
- (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;
}
/**
*? 判斷某個時間是否為今天
*/
- (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
