iOS一个时间距现在的时间方法 intervalSinceNow NSDateFormatter

- (NSString*)intervalSinceNow:(NSString*)theDate

{

    NSArray* timeArray = [theDate componentsSeparatedByString:@"."];

    theDate = [timeArray objectAtIndex:0];

 

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

    [date setDateFormat:@"yyyy-MM-dd HH:mm:ss"];

    NSDate* d = [date dateFromString:theDate];

 

    NSTimeInterval late = [d timeIntervalSince1970] * 1;

 

    NSDate* dat = [NSDate date];

    NSTimeInterval now = [dat timeIntervalSince1970] * 1;

    NSString* timeString = @"";

 

    NSTimeInterval cha = now - late;

 

    if (cha / 3600 < 1) {

        timeString = [NSString stringWithFormat:@"%f", cha / 60];

        timeString = [timeString substringToIndex:timeString.length - 7];

        timeString = [NSString stringWithFormat:@"%@分", timeString];

    }

    else if (cha / 86400 < 1) {

        timeString = [NSString stringWithFormat:@"%f", cha / 3600];

        timeString = [timeString substringToIndex:timeString.length - 7];

        timeString = [NSString stringWithFormat:@"%@小时", timeString];

    }

    else if (cha / (86400 * 30) < 1) {

        timeString = [NSString stringWithFormat:@"%f", cha / 86400];

        timeString = [timeString substringToIndex:timeString.length - 7];

        timeString = [NSString stringWithFormat:@" %@天", timeString];

    }

    else if (cha / (86400 * 30 * 12) < 1) {

        timeString = [NSString stringWithFormat:@"%f", cha / (86400 * 30)];

        timeString = [timeString substringToIndex:timeString.length - 7];

        timeString = [NSString stringWithFormat:@" %@月", timeString];

    }

    else {

        timeString = [NSString stringWithFormat:@"%f", cha / (86400 * 30 * 12)];

        timeString = [timeString substringToIndex:timeString.length - 7];

        timeString = [NSString stringWithFormat:@" %@年", timeString];

    }

    return timeString;

}