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我dequeueReusableCellWithIdentifier:使用UITableView. 不知道我是不是对这个方法理解得不够好，还是很奇怪。开始：

我使用一个UITableView向用户提供一些数据的方法，在我的内部我
- (UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath使用 dequeue 方法，如下所示：

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"cell"];
    if (!cell)
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"];

之后，我将一些子视图添加到contentView单元格的属性中。当在我的表格上向下滚动一点时，我看到了那些先前添加的子视图，即单元格不是空的，而是充满了“旧”数据。如果我不出队，并且alloc-init每次只有一个新的，单元格是空的，但我确实看到更多的内存消耗，这正是我试图降低的一点。如果这意味着什么，我正在使用 ARC。

我应该怎样或如何解决这个问题？我尝试for在内容视图的子视图中运行一个循环，[view removeFromSuperview]它确实删除了以前的视图并稍微降低了内存消耗。但这真的有必要吗？或者，还有更好的方法？

编辑这里是我如何添加子视图的更多代码

cell.backgroundView = [[UIView alloc] initWithFrame:cell.frame];
cell.backgroundColor = kClearColor; //defined to [UIColor clearColor]
cell.selectionStyle = UITableViewCellSelectionStyleNone;

if (indexPath.row == 0)
{
    UIImageView *shine = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 50)];
    shine.image = [UIImage imageNamed:@"top_shine_1"];
    [cell.backgroundView addSubview:shine]; //its a gradient thats why its added to background

    UILabel *appLabel = [[UILabel alloc] initWithFrame:CGRectMake(55, winSize.height * 0.027, 250, 33)];
    appLabel.backgroundColor = kClearColor; //defined to clear color
    appLabel.textColor = kWhiteColor; //defined to white color
    appLabel.text = [viewOrder objectAtIndex:tableView.tag]; //just an array from where I get the required text
    appLabel.font = kStandardFontOfSize(30); //defined to a specific font

    [cell.contentView addSubview:appLabel];

    UIButton *settingsButton = [UIButton buttonWithType:UIButtonTypeCustom];
    settingsButton.frame = CGRectMake(10, winSize.height * 0.0377, 31, 21);
    [settingsButton setImage:[UIImage imageNamed:@"settings_button"] forState:UIControlStateNormal];
    [settingsButton addTarget:self action:@selector(settings:) forControlEvents:UIControlEventTouchUpInside];

    [cell.contentView addSubview:settingsButton];

    return cell; //here I just return it since this is all the config the first cell needs
}

NSString *app = [viewOrder objectAtIndex:tableView.tag];
NSArray *boxes = [[plist secondObjectForKey:@"order" parent:app] componentsSeparatedByString:@";"];

//Add necessary shines or create the last logotype cell - just some details and stuff, all are just images
if (indexPath.row == 1)
{
    UIImageView *shine = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 282.5)];
    shine.image = [UIImage imageNamed:@"top_shine_2"];

    [cell.backgroundView addSubview:shine];
}
else if (indexPath.row == 2)
{
    UIImageView *shine = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, winSize.width, 150)];
    shine.image = [UIImage imageNamed:@"main_shine"];

    [cell.backgroundView addSubview:shine];
}
else if (indexPath.row == boxes.count + 1)
{
    UIImageView *logo = [[UIImageView alloc] initWithFrame:CGRectMake(111.5, 25, 97, 20)];
    logo.image = [UIImage imageNamed:@"cell_logo"];

    [cell.backgroundView addSubview:logo];
    return cell;
}

NSString *databox = [boxes objectAtIndex:indexPath.row - 1];
UIView *view; //Main subview to be added to the cell

/*
    here I have a class that creates a view with a bunch of subviews added to that view, the view is then assigned to 'view'; kinda like
view = [someAssembler assembleViewWith:options.....]. all are basically UILabels or ImageViews added to the main view
*/

[cell.contentView addSubview:view]; //and here this 'main view' is added as a subview, this view is still visible after the cell has been dequeued and the shines are as well

return cell;

在你开始批评我为什么不使用单一UIColor的背景和文本颜色之前，让我提醒你，这仍处于测试阶段，稍后会处理。

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1 回答 1

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[cell.backgroundView addSubview:shine];这些代码行是您的问题。

您应该在 if (!cell) 块中创建一个完整的可重用单元，并在每次cellForRow调用时重新填充它们。对于每个唯一的单元格，都应该使用唯一的重用标识符。例如，如果您有多个具有不同布局子视图的单元格，您应该为它们使用不同的标识符。

在您的特定示例中，必须在if (indexPath.row == 1)块中创建单元格。

static NSString *cellIdentifier = @"cell";
UITableViewCell *cell = nil;

if (indexPath.row == 0) {
  cellIdentifier = @"topCell";
  cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier];
  if (!cell) {
    // create the cell and add the necessary subviews for indexPath row 0
  }
  return cell;
}
else if (indexPath.row == 1) {

}

//etc.

}

但是，您必须使用这种方法为 !cell 块中的每个单元格创建“主子视图”，因此您可能应该考虑对单元格进行子类化。

于 2013-08-24T09:37:18.687 回答