ios - tableViewController 不同单元格中的不同图像无法正常工作

Question

我做了一个tableViewController。我想为第一个和第七个索引单元格提供不同的图像。这是我的 cellForRowAtIndexPath 委托(delegate)方法中的代码片段。它在开始时正确地初始化了单元格，但是当我上下滚动几次时，它也开始在其他单元格的附件 View 中给出“button4.png”。

                UIImage *indicatorImage;
            if(indexPath.row==0||indexPath.row==6)
            {
                indicatorImage = [UIImage imageNamed:@"button4.png"];
            }
            else
            {
                indicatorImage = [UIImage imageNamed:@"img-arrow.png"];
            }      

        cell.accessoryView =
        [[UIImageView alloc]
          initWithImage:indicatorImage];

这可能是什么原因？

函数的完整代码有点乱，我贴在这里:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    selection=self.tabBarController.selectedIndex;
    static NSString *CellIdentifier = @"Cell";
    UILabel *topLabel;

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

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

        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
        UIImage *indicatorImage;



        if(indexPath.row==0||indexPath.row==6)
        {
            indicatorImage = [UIImage imageNamed:@"button4.png"];
        }
        else
        {
            indicatorImage = [UIImage imageNamed:@"img-arrow.png"];
        }      

    cell.accessoryView =
    [[UIImageView alloc]
      initWithImage:indicatorImage];

        cell.accessoryView =
        [[UIImageView alloc]
          initWithImage:indicatorImage];
        const CGFloat LABEL_HEIGHT = 20;



        topLabel =
        [[UILabel alloc]
          initWithFrame:
          CGRectMake(
                     2.0 * cell.indentationWidth,
                     0.5 * (tableView.rowHeight - 2 * LABEL_HEIGHT),
                     tableView.bounds.size.width -
                     4.0 * cell.indentationWidth
                     - indicatorImage.size.width,
                     LABEL_HEIGHT)];

        [cell.contentView addSubview:topLabel];

        topLabel.backgroundColor = [UIColor clearColor];
        topLabel.shadowColor = [UIColor whiteColor];
        topLabel.shadowOffset = CGSizeMake(0, 1);
        topLabel.textColor = [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:1.0];
        topLabel.highlightedTextColor = [UIColor colorWithRed:1.0 green:1.0 blue:0.9 alpha:1.0];
        topLabel.font = [UIFont systemFontOfSize:[UIFont labelFontSize]];

        topLabel.tag=10;
        cell.backgroundView =
        [[UIImageView alloc] init];
        cell.selectedBackgroundView =
        [[UIImageView alloc] init];

    }
}
else
{
    topLabel = (UILabel *)[cell viewWithTag:10];
}

UIImage *rowBackground;
UIImage *selectionBackground;


rowBackground = [UIImage imageNamed:@"topAndBottomRow.png"];
selectionBackground = [UIImage imageNamed:@"topAndBottomRowSelected.png"];


    if(indexPath.row==0||indexPath.row==6)
    {

        rowBackground = [UIImage imageNamed:@"topAndBottomRowSelected.png"];
        selectionBackground = [UIImage imageNamed:@"topAndBottomRowSelected.png"];

        topLabel.textColor = [UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:1.0];
        topLabel.highlightedTextColor = [UIColor colorWithRed:1.0 green:1.0 blue:0.9 alpha:1.0];
        topLabel.font = [UIFont systemFontOfSize:20];
    }


((UIImageView *)cell.backgroundView).image = rowBackground;
((UIImageView *)cell.selectedBackgroundView).image = selectionBackground;


NSString *object = _objects[indexPath.row];
NSString *str=[object description];
topLabel.text=[NSString stringWithFormat:@"         %@",str];

return cell;

Answer 1

您在创建和配置单元格的 if (cell == nil) ... block 中设置此图像。但是您需要将此图像设置移到 if block 之外，因为如果单元格被重用(即您不必 alloc 和 init)，旧图像将被重新使用。您应该检查 if 语句中的任何内容，以了解应该逐个单元更改的内容，并将其移出 if block 。