ios - 闪烁图像 tableview 重用错误请参阅视频链接 -->http ://www. youtube.com/watch?v=jwEsqjc9sNc&feature=youtu.be

Question

代码如下:我在后台从我的核心数据下载图像并将其放在我的 ImageView 中。

static NSString *cellIdentifier = @"Pubs Cell";
PubsCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];

Pub *current = [self.fetchController objectAtIndexPath:indexPath];

cell.name.text = current.name;
cell.description.text = current.descriptionText;
cell.description.backgroundColor = [UIColor clearColor];
cell.description.editable = NO;
dispatch_queue_t queue = dispatch_queue_create("image_queue", NULL);
dispatch_async(queue, ^{
    NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@",current.photo]]];
    dispatch_async(dispatch_get_main_queue(), ^{

        cell.pubImage.image = [UIImage imageWithData:data];
    });
});
cell.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"light1.jpg"]];

return cell;

有什么解决办法吗？提前致谢。

Answer 1

在开始异步加载任务之前，您需要将图像设置为 nil:

// removing the old image from the reused tablecell
cell.pubImage.image = nil;

// load image asynchronously
dispatch_queue_t queue = dispatch_queue_create("image_queue", NULL);
dispatch_async(queue, ^{
    NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString stringWithFormat:@"%@",current.photo]]];
    dispatch_async(dispatch_get_main_queue(), ^{
        cell.pubImage.image = [UIImage imageWithData:data];
    });
});

这是因为加载图像需要一些时间，所以您会看到旧图像，因为表格单元格在可用时会被重用。