更新 UITableCell 中的计时器值

Question

我有一个计时器，它每秒调用 updateInterval 。该计时器将计算剩余时间并将结果作为 NSString。换句话说，NSString 每秒都在变化，从我下面所做的来看，UITable 然后每 1 秒重新加载一次。问题是它在 countdown.text = labelText; 时崩溃，

  // inside - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
//blah
 else if (indexPath.row == 1 && indexPath.section == 0){
        UILabel * countdown = [[UILabel alloc] init];
        countdown.text = labelText;
        [cell.contentView addSubview:countdown];
        cell.textLabel.text = @"Time remaining";
    }
//blah

- (void)updateInterval:(NSTimer *)timer {
    NSTimeInterval timeinterval = [(NSDate *)[data valueForKey:@"start_date"] timeIntervalSinceDate:[NSDate date]];

    // Get the system calendar
    NSCalendar *sysCalendar = [NSCalendar currentCalendar];

    // Create the NSDates
    NSDate *date1 = [[NSDate alloc] init];
    NSDate *date2 = [[NSDate alloc] initWithTimeInterval:timeinterval sinceDate:date1]; 

    // Get conversion to months, days, hours, minutes
    unsigned int unitFlags = NSHourCalendarUnit | NSMinuteCalendarUnit | NSDayCalendarUnit | NSMonthCalendarUnit | NSSecondCalendarUnit;

    NSDateComponents *breakdownInfo = [sysCalendar components:unitFlags fromDate:date1  toDate:date2  options:0];

    labelText = [NSString stringWithFormat:@"%d day %d:%d:%d", [breakdownInfo day], [breakdownInfo hour], [breakdownInfo minute], [breakdownInfo second]];
    //NSLog(@"%d day %d:%d:%d", [breakdownInfo day], [breakdownInfo hour], [breakdownInfo minute], [breakdownInfo second]);
    [self.table reloadData];
    [date1 release];
    [date2 release];

}

这是为什么？

Answer 1

如果您在控制台中访问不良，则可能是因为您必须在 updateInterval 方法中保留 labelText。