UITableViewCell 中的 UILabel 重叠

Question

我有 2x UILabels，1 个标题 1 个副标题， 当选择segmentedControl 时，它们会发生变化。

它有效，但当选择不同的段时，我得到相同的 UILabel 重叠自身？

我想我需要创建一个操作来从超级视图中删除标签，然后再将其重新显示到单元格上？只是想知道如何去做

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

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

    EventUpcoming *aEventUpcoming = [euEvent objectAtIndex:indexPath.section];
    EventWeekly *aEventWeekly = [ewEvent objectAtIndex:indexPath.section];

    UILabel *cellTitle = [[UILabel alloc] initWithFrame:CGRectMake(15, 5, 290, 20)];
    UILabel *cellSubtitle = [[UILabel alloc] initWithFrame:CGRectMake(15, 20, 290, 20)];

    NSString *titleString = [[NSString alloc] init];
    NSString *subtitleString = [[NSString alloc] init];

    if (segmentedControl.selectedSegmentIndex == 0) 
    {
        Event *aEvent = [aEventUpcoming.event objectAtIndex:indexPath.row];
        titleString = aEvent.name;
        subtitleString = aEvent.subtitle;
    } 
    else 
    {
        Event *aEvent = [aEventWeekly.event objectAtIndex:indexPath.row];
        titleString = aEvent.name;
        subtitleString = aEvent.subtitle;
    }

    NSString *titleStringUC = [titleString uppercaseString];
    NSString *subtitleStringLC = [subtitleString lowercaseString];

    cellTitle.text = titleStringUC;
    cellTitle.font = [UIFont boldSystemFontOfSize:11];
    cellTitle.textColor = [UIColor colorWithRed:142/255.0f green:142/255.0f blue:142/255.0f alpha:1];
    cellTitle.shadowColor = [UIColor whiteColor];
    cellTitle.shadowOffset = CGSizeMake(1, 1);
    cellTitle.backgroundColor = [UIColor clearColor];

    cellSubtitle.text = subtitleStringLC;
    cellSubtitle.font = [UIFont boldSystemFontOfSize:11];
    cellSubtitle.textColor = [UIColor colorWithRed:177/255.0f green:177/255.0f blue:177/255.0f alpha:1];
    cellSubtitle.shadowColor = [UIColor whiteColor];
    cellSubtitle.shadowOffset = CGSizeMake(1, 1);
    cellSubtitle.backgroundColor = [UIColor clearColor];


    tableViewCellSeparator = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"TableCellSeparator.png"]];
    tableViewCellSeparator.frame = CGRectMake(0, cell.bounds.size.height - 2, 320, 2);

    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

    [cell.contentView addSubview:cellTitle];
    [cell.contentView addSubview:cellSubtitle];
    [cell.contentView addSubview:tableViewCellSeparator];






    return cell;
}

---

更新：
两个都是非常有效的答案，tyvm

Answer 1

您没有正确地重用单元，因此您没有获得重用的性能优势，并使代码变得更加复杂。你也没有使用苹果为你提供的开箱即用的部件。

首先，您应该在 cell==nil 块内创建并添加所有子视图。这是您创建可重复使用单元的地方。在例程的其余部分中，您只需重新配置单元。这要快得多。

其次，UITableViewCell 已经内置了两个标签。您不需要创建它们。它们称为 textLabel 和 detailTextLabel。它们是普通的标签；您可以移动它们并使它们看起来像您想要的任何形状。在 cell==nil 块中执行此操作。

然后，您只需在 cell==nil 之外调用 cell.textLabel.text = ... 和 cell.detailTextLabel.text = ... code> block 就可以了。

如果您需要两个以上的标签，那么我将子类化 UITableViewCell 并在其上创建新属性，以便您可以轻松地重新配置单元格。

Answer 2

我希望它现在可以工作。试试这个......

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";

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


    EventUpcoming *aEventUpcoming = [euEvent objectAtIndex:indexPath.section];
    EventWeekly *aEventWeekly = [ewEvent objectAtIndex:indexPath.section];

    UILabel *cellTitle = [[UILabel alloc] initWithFrame:CGRectMake(15, 5, 290, 20)];
    UILabel *cellSubtitle = [[UILabel alloc] initWithFrame:CGRectMake(15, 20, 290, 20)];

    NSString *titleString = [[NSString alloc] init];
    NSString *subtitleString = [[NSString alloc] init];

    NSString *titleStringUC = [titleString uppercaseString];
    NSString *subtitleStringLC = [subtitleString lowercaseString];

    cellTitle.text = titleStringUC;
    cellTitle.font = [UIFont boldSystemFontOfSize:11];
    cellTitle.textColor = [UIColor colorWithRed:142/255.0f green:142/255.0f blue:142/255.0f alpha:1];
    cellTitle.shadowColor = [UIColor whiteColor];
    cellTitle.shadowOffset = CGSizeMake(1, 1);
    cellTitle.backgroundColor = [UIColor clearColor];
    cellTitle.tag = 10;

    cellSubtitle.text = subtitleStringLC;
    cellSubtitle.font = [UIFont boldSystemFontOfSize:11];
    cellSubtitle.textColor = [UIColor colorWithRed:177/255.0f green:177/255.0f blue:177/255.0f alpha:1];
    cellSubtitle.shadowColor = [UIColor whiteColor];
    cellSubtitle.shadowOffset = CGSizeMake(1, 1);
    cellSubtitle.backgroundColor = [UIColor clearColor];
    cellSubtitle.tag = 11;


    tableViewCellSeparator = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"TableCellSeparator.png"]];
    tableViewCellSeparator.frame = CGRectMake(0, cell.bounds.size.height - 2, 320, 2);

    cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;


    [cell.contentView addSubview:cellTitle];
    [cell.contentView addSubview:cellSubtitle];
    [cell.contentView addSubview:tableViewCellSeparator];
}

cellTitle = (UILabel *)[cell.contentView viewWithTag:10];
 cellSubtitle = (UILabel *)[cell.contentView viewWithTag:11];

if (segmentedControl.selectedSegmentIndex == 0) 
{
    Event *aEvent = [aEventUpcoming.event objectAtIndex:indexPath.row];
    titleString = aEvent.name;
    subtitleString = aEvent.subtitle;
} 
else 
{
    Event *aEvent = [aEventWeekly.event objectAtIndex:indexPath.row];
    titleString = aEvent.name;
    subtitleString = aEvent.subtitle;
}

return cell;
}