objective-c 图像未出现在自定义 UITableViewCell 中

Question

我有 NSMutableArray ，它包含字符串、日期时间和UIImage。 一切都显示在我的 UITableView 中，没有图像。

  - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

        static NSString *cellIdentifier =@"Cell";
        CustomCell *customCell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];

        contact = res[indexPath.row];

        NSString *titleNews = contact[@"title"];
        NSString *newsDateTime = contact[@"datetime"];
        NSString *NewsImageName = contact[@"featured_image"];

        UIImage *image = [UIImage imageNamed:NewsImageName ];

        customCell.customFirstNameLabel.text = titleNews;
        customCell.customLastnameLabel.text = newsDateTime;
        customCell.customImageView.image =image;

        return customCell;
    }

我正在尝试从这里显示数据。

{
        datetime = "2015-09-10 13:35:33";
        "featured_image" = "http://198.72.115.125/~pratidin/assets/news_images/2015/09/10/thumbnails/bdp-001.jpg";
        "item_id" = 102235;
        "main_news_url" = "http://198.72.115.125/~pratidin/api/detailnews/102235";
        "main_url" = "http://198.72.115.125/~pratidin/api/topnews";
        summery = "\U0997\U09a4 \U0995\U09af\U09bc\U09c7\U0995\U09ae\U09be\U09b8 \U09af\U09be\U09ac\U09a4 \U09ae\U09cb\U09ac\U09be\U0987\U09b2\U09aa\U09cd\U09b0\U09c7\U09ae\U09c0\U09b0\U09be \U0985\U09aa\U09c7\U0995\U09cd\U09b7\U09be\U09af\U09bc…";
        title = "\U098f\U09ac\U09be\U09b0 \U0986\U0987\U09ab\U09cb\U09a8 \U09ec\U098f\U09b8 \U0993 \U09ec\U098f\U09b8 \U09aa\U09cd\U09b2\U09be\U09b8";
    }

这是我的看法。 有人能帮我解决这个问题吗

Answer 1

它的图片url……你不能直接通过图片名设置图片……你必须像这样从url获取数据……

NSURL *imgURL = [NSURL URLWithString:NewsImageName];

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0), ^{
NSData *imgData = [NSData dataWithContentsOfURL:imgURL];

  dispatch_async(dispatch_get_main_queue(), ^{
        imageView.image = [UIImage imageWithData:imgData];
   });
});

或者直接设置

UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL: NewsImageName]];

Answer 2

这里您的数据源联系人[@"featured_image"] 是一个网址。所以你必须从 url 加载图像。你可以使用 SDWebImage.framework 来加载图片

            [cell.imageview sd_setImageWithURL:[NSURL URLWithString:contact[@"featured_image"]] placeholderImage:nil options:SDWebImageCacheMemoryOnly completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
                if (image) {
                     [cell.imageview setImage:image];
                }
            }];

Answer 3

您必须先从 URL 加载图像内容：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *cellIdentifier =@"Cell";
    CustomCell *customCell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier forIndexPath:indexPath];

    contact = res[indexPath.row];

    NSString *titleNews = contact[@"title"];
    NSString *newsDateTime = contact[@"datetime"];
    NSString *NewsImageName = contact[@"featured_image"];

    UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:NewsImageName]]];
    //UIImage *image = [UIImage imageNamed:NewsImageName ];

    customCell.customFirstNameLabel.text = titleNews;
    customCell.customLastnameLabel.text = newsDateTime;
    customCell.customImageView.image =image;

    return customCell;
}

请注意，这将是图像的同步获取。我建议你检查 LazyTableImages 函数：https://developer.apple.com/library/ios/samplecode/LazyTableImages/Introduction/Intro.html 或任何图像缓存库，如https://github.com/rs/SDWebImage

Answer 4

请 NSLog 你的图片，以及 imageView 的框架。

而[UIImage imageNamed:NewsImageName ]; 仅从主包加载，看起来您正在从互联网加载图像。

另一种可能是你设置了错误的框架，所以它消失了。

你应该这样写

NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageURL]];

UIImage *img = [[UIImage alloc] initWithData:data];

Answer 5

试试这个

UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL: NewsImageName]];