PickerView计算剩余时间,主要是时间方面的转换

//计算剩余时间
-(void)getNowTimeDate:(NSString*)dateStr
{
    //将传入时间NSString转化成需要的格式
    NSDateFormatter *format=[[NSDateFormatteralloc]init];
    [format setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSDate *fromdate=[format dateFromString:dateStr];
    NSTimeZone *fromzone = [NSTimeZonesystemTimeZone];
    NSInteger frominterval = [fromzone secondsFromGMTForDate: fromdate];
    NSDate *fromDate = [fromdate  dateByAddingTimeInterval: frominterval];
    NSLog(@"fromdate=%@",fromDate);
    //获取当前时间
    NSDate *date = [NSDatedate];
    NSTimeZone *zone = [NSTimeZonesystemTimeZone];
    NSInteger interval = [zone secondsFromGMTForDate: date];
    NSDate *localeDate = [date  dateByAddingTimeInterval: interval];
    NSLog(@"enddate=%@",localeDate);
   
   
    double intervalTime = [fromDate timeIntervalSinceReferenceDate] - [localeDatetimeIntervalSinceReferenceDate];
   
    long lTime = (long)intervalTime;
    NSInteger iSeconds = lTime % 60;
    NSInteger iMinutes = (lTime / 60) %60;
    NSInteger iHours = (lTime / 3600)%24;
    NSInteger iDays = lTime/60/60/24;
    NSInteger iMonth = lTime/60/60/24/12;
    NSInteger iYears = lTime/60/60/24/384;
    _surplusStr = [NSStringstringWithFormat:@"%d年%d月%d日%.2d:%.2d:%.2d",iYears,iMonth,iDays,iHours,iMinutes,iSeconds];
   

}

//PickerView改变时的处理
-(void)dateChange
{

   //将NSDate 转化成NSString
    NSDate * selected = [_datePickerdate];
    NSDateFormatter * dateFormatter = [[NSDateFormatteralloc]init];
    [dateFormatter setDateFormat:@"yyyy/MM/dd HH:mm:ss"];
    NSString *destDateString = [dateFormatter stringFromDate:selected];
    _dataStr = destDateString;
    [selfgetNowTimeDate:destDateString];
    [_tableViewreloadData];
    CGPoint offset = [_tableViewcontentOffset];
    offset.y= offset.y+PikerViewH;
    _tableView.contentOffset= offset;
    _tableView.contentSize=CGSizeMake(SCREEN_W, offset.y+SCREEN_H);
   

}