时间转换，用于倒计时

//将时间转换成秒 time为 YYYY-MM-dd HH:mm:ss 格式

-(NSString *) getSecondsWithTime:(NSString *)time
{
    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
    [formatter setDateFormat:@"YYYY-MM-dd HH:mm:ss"];
    NSDate *date = [formatter dateFromString:time];
    NSString *timeStr = [NSString stringWithFormat:@"%ld",(long)[date timeIntervalSince1970]];
    return timeStr;
}

//将秒转换成时间

-(NSString *) getTimeWithSeconds:(NSString *)seconds
{
    NSInteger time=[seconds longLongValue];
    NSDate *d = [[NSDate alloc]initWithTimeIntervalSince1970:time];
    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
            [formatter setLocale:[NSLocale systemLocale]];
    [formatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString*timeString=[formatter stringFromDate:d];
    return timeString;
}

//转换成 时分秒

-(NSString *)timeFormatted:(NSInteger)totalSeconds
{
    NSInteger seconds = totalSeconds % 60;
    NSInteger minutes = (totalSeconds / 60) % 60;
    NSInteger hours = totalSeconds / 3600;
    return [NSString stringWithFormat:@"%02ld:%02ld:%02ld",hours, minutes, seconds];
}