ios - 为什么旧值出现在tableViewCell中

Question

我在制作TableViewCell时添加了一个UILabel。代码如下:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    Special *special = [speciales objectAtIndex:indexPath.row];
    ......
    UILabel *description = [[UILabel alloc] initWithFrame:CGRectMake(80, 21, 220, 50)];
    description.text = special.specialDescription;
    description.font = [UIFont fontWithName:@"Heiti SC" size:12];
    description.textColor = [UIColor darkGrayColor];
    description.lineBreakMode = UILineBreakModeWordWrap;
    description.numberOfLines = 3;

    [cell addSubview:description];

    return cell;
}

它运行良好，但是当我从下到上滚动它并选择一行时，旧值同时出现。谁能帮我解决这个问题？

谢谢!

更新:我的所有代码都是这样的:- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

Special *special = [speciales objectAtIndex:indexPath.row];

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}

UIImageView *img = [[UIImageView alloc] initWithFrame:CGRectMake(10, 5, 60, 60)];
img.image = special.specialIconImage;

[self addShadowToImage:img];

[cell addSubview:img];

UILabel *name = [[UILabel alloc] initWithFrame:CGRectMake(80, 5, 220, 16)];
name.text = special.specialName;

name.font = [UIFont fontWithName:@"Heiti SC" size:16];

[cell addSubview:name];

UILabel *description = [[UILabel alloc] initWithFrame:CGRectMake(80, 21, 220, 50)];
description.text = special.specialDescription;
description.font = [UIFont fontWithName:@"Heiti SC" size:12];
description.textColor = [UIColor darkGrayColor];
description.lineBreakMode = UILineBreakModeWordWrap;
description.numberOfLines = 3;

[cell addSubview:description];

return cell;

Answer 1

问题是您每次调用单元格时都会添加图像和标签 subview 。相反，您只想在创建单元格时添加这些 subview 。每次调用单元格时，您只想设置 subview 的值。你会想要这样的东西(凭内存完成):

Special *special = [speciales objectAtIndex:indexPath.row];

static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];

    UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 5, 60, 60)];
    [imageView setTag:100];
    [cell addSubview:imageView];

    UILabel *nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(80, 5, 220, 16)];
    name.font = [UIFont fontWithName:@"Heiti SC" size:16];
    [nameLabel setTag:101];
    [cell addSubview:nameLabel];

    UILabel *descriptionLabel = [[UILabel alloc] initWithFrame:CGRectMake(80, 21, 220, 50)];
    [descriptionLabel setTag:102];
    descriptionLabel.font = [UIFont fontWithName:@"Heiti SC" size:12];
    descriptionLabel.textColor = [UIColor darkGrayColor];
    descriptionLabel.lineBreakMode = UILineBreakModeWordWrap;
    descriptionLabel.numberOfLines = 3;
    [cell addSubview:descriptionLabel];
}

UIImageView *img = (UIImageView *)[cell viewWithTag:100];
img.image = special.specialIconImage;
[self addShadowToImage:img];

UILabel *name = (UILabel *)[cell viewWithTag:101];
name.text = special.specialName;

UILabel *description = (UILabel *)[cell viewWithTag:102];
description.text = special.specialDescription;

return cell;