objective-C日期相关操作

1、获取当前日期、时间

    NSDate *currentDate = [NSDate date];

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

    [dateFormatter setDateFormat:@"YYYY-MM-dd"];

    NSString *currentDateStr = [dateFormatter stringFromDate:currentDate];

2、获取一周前的日期、时间

    NSDate * date = [NSDate date];

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

    [dateFormatter setDateFormat:@"yyyy-MM-dd"];

    //一周的秒数

    NSTimeInterval time = 7 * 24 * 60 * 60;

    //下周就把"-"去掉

    NSDate *lastWeek = [date dateByAddingTimeInterval:-time];

    NSString *startDate =  [dateFormatter stringFromDate:lastWeek];

3、比较两个日期大小

-(NSInteger)compareDate:(NSString*)startDate withDate:(NSString*)endDate{

    NSInteger comparisonResult;

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

    [formatter setDateFormat:@"yyyy-MM-dd"];

    NSDate *date1 = [[NSDate alloc] init];

    NSDate *date2 = [[NSDate alloc] init];

    date1 = [formatter dateFromString:startDate];

    date2 = [formatter dateFromString:endDate];

    NSComparisonResult result = [date1 compare:date2];

    NSLog(@"result==%ld",(long)result);

    switch (result)

    {

            //date02比date01大

        case NSOrderedAscending:

            comparisonResult = 1;

            break;

            //date02比date01小

        case NSOrderedDescending:

            comparisonResult = -1;

            break;

            //date02=date01

        case NSOrderedSame:

            comparisonResult = 0;

            break;

        default:

            NSLog(@"erorr dates %@, %@", date1, date2);

            break;

    }

    return comparisonResult;

}

//与当前日期对比( 作为NSString + Extension)

-(NSInteger)compareWithCurrentDate {

    

    if (self.length != 8) {

        RFLog(@"传入的格式错误！");

        return 1000;//本地自定义的错误码

    }

    

    NSInteger comparisonResult;

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

    [formatter setDateFormat:@"yyyyMMdd"];

    NSDate *date1 = [[NSDate alloc] init];

    NSDate *date2 = [NSDate date];

    date1 = [formatter dateFromString:self];

    NSComparisonResult result = [date1 compare:date2];

    switch (result)

    {

            //date2比date1大

        case NSOrderedAscending:

            comparisonResult = 1;

            break;

            //date2比date1小

        case NSOrderedDescending:

            comparisonResult = -1;

            break;

            //date2=date1

        case NSOrderedSame:

            comparisonResult = 0;

            break;

        default:

            NSLog(@"erorr dates %@, %@", date1, date2);

            break;

    }

    return comparisonResult;

}

4、比较日期差

-(NSInteger)compare:(NSDate *)startTime to:(NSDate *)endTime{

    // 当前日历

    NSCalendar *calendar = [NSCalendar currentCalendar];

    // 需要对比的时间数据

    NSCalendarUnit unit = NSCalendarUnitYear | NSCalendarUnitMonth

    | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;

    // 对比时间差

    NSDateComponents *dateCom = [calendar components:unit fromDate:startTime toDate:endTime options:0];

    NSString *time = [NSString stringWithFormat:@"%ld%ld%ld%ld%ld%ld",dateCom.year,dateCom.month,dateCom.day,dateCom.hour,dateCom.minute,dateCom.second];

    NSLog(@"time---->%@",time);

    return [time integerValue];

}

5、时间和时间戳的转换

    NSDate* date1 = [NSDate date];

    NSTimeInterval time1 =[date1 timeIntervalSince1970];

    NSString *timeString = [NSString stringWithFormat:@"%.0f",time1];

    NSLog(@"系统时间戳:%@",timeString);

    //时间戳转换成时间

    NSTimeInterval time2 =[timeString doubleValue];

    NSDate *date2 = [NSDate dateWithTimeIntervalSince1970:time2];

    NSLog(@"date2 = %@",date2);

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

    [formatter setDateFormat:@"yyyy/MM/dd"];

    NSString *currentTime = [formatter stringFromDate:date2];

    NSLog(@"当前时间:%@",currentTime);

    //时间转时间戳

    NSString *timeStr = [NSString stringWithFormat:@"%.0f",[date2 timeIntervalSince1970]];

    NSLog(@"时间戳：%@",timeStr);

转载

文／来宝（简书作者）

原文链接：http://www.jianshu.com/p/23f9c6a0e8f2

著作权归作者所有，转载请联系作者获得授权，并标注“简书作者”。