• 场景需求:从网络请求返回的时间数据一般是时间字符串,比如@"2015-10-31 23:07:08"对这个时间字符串进行判断,截取,转换成我们想要的格式;比如

时间字符串操作要求.png

#import <Foundation/Foundation.h>
@interface NSDate (DXExtension)
- (BOOL)isThisYear;
- (BOOL)isToday;
- (BOOL)isYesterday;
- (BOOL)isInOneMinute;
- (BOOL)isInOneHour;
- (BOOL)isTomorrow;
@end

@implementation NSDate (DXExtension)

static NSDateFormatter *formatter_;
static  NSCalendar *calendar_;

// 第一次使用这个类的时候调用
// 优化性能,减少频繁的创建格式化对象
+ (void)initialize
{
    formatter_ = [[NSDateFormatter alloc] init];
    calendar_ = [NSCalendar calendar];
}
- (BOOL)isToday
{
    formatter_.dateFormat = @"yyyyMMdd";
    
    NSString *selfDay = [formatter_ stringFromDate:self];
    NSString *nowDay = [formatter_ stringFromDate:[NSDate date]];
    
    return [selfDay isEqualToString:nowDay];
}

- (BOOL)isYesterday
{
    formatter_.dateFormat = @"yyyyMMdd";
    
    NSString *selfDay = [formatter_ stringFromDate:self];
    NSString *nowDay = [formatter_ stringFromDate:[NSDate date]];
    
    NSDate *selfDate = [formatter_ dateFromString:selfDay];
    NSDate *nowDate = [formatter_ dateFromString:nowDay];
    
    NSCalendarUnit units = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
    NSDateComponents *cmp = [calendar_ components:units fromDate:nowDate toDate:selfDate options:0];
    
    return cmp.year == 0 && cmp.month == 0 && cmp.day == 1;
}

- (BOOL)isTomorrow
{
    formatter_.dateFormat = @"yyyyMMdd";
    
    NSString *selfDay = [formatter_ stringFromDate:self];
    NSString *nowDay = [formatter_ stringFromDate:[NSDate date]];
    
    NSDate *selfDate = [formatter_ dateFromString:selfDay];
    NSDate *nowDate = [formatter_ dateFromString:nowDay];
    
    NSCalendarUnit units = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
    NSDateComponents *cmp = [calendar_ components:units fromDate:nowDate toDate:selfDate options:0];
    
    return cmp.year == 0 && cmp.month == 0 && cmp.day == -1;
}

- (BOOL)isThisYear
{
    formatter_.dateFormat = @"yyyy";
    NSString *selfYear = [formatter_ stringFromDate:self];
    NSString *currentYear = [formatter_ stringFromDate:[NSDate date]];
    
    return [selfYear isEqualToString:currentYear];
}
- (BOOL)isInOneMinute
{
    formatter_.dateFormat = @"yyyyMMddHHmm";
    
    NSString *selfSecond = [formatter_ stringFromDate:self];
    NSString *nowSecond = [formatter_ stringFromDate:[NSDate date]];
    
    return [selfSecond isEqualToString:nowSecond];
}

- (BOOL)isInOneHour
{
    formatter_.dateFormat = @"yyyyMMddHH";
    
    NSString *selfHour = [formatter_ stringFromDate:self];
    NSString *nowHour = [formatter_ stringFromDate:[NSDate date]];
    
    return [selfHour isEqualToString:nowHour];
    
}
@end