ios - 从返回 SIGABRT 的 Web 服务访问字典对象

Question

我有一个表格 View ，我希望在其中的每个单元格中填充来自网络服务的数据。每个单元格都应该显示对象的名称、价格和品牌名称。我可以很好地获得名称，但价格和品牌名称并不那么容易。我检查了网络服务，它确实有价格和品牌名称，所以这肯定是我的代码有问题。到目前为止，它是这样的:

    for (NSDictionary *objItem in resultsArray)
{
     NSString *currentItemName = [objectTitlesArray objectAtIndex:indexPath.row];

    if ([currentItemName isEqualToString:objItem[@"title"]])
    {
        cell.nameLabel.text = currentItemName;
        cell.priceLabel.text = objItem[@"price"];
        cell.brandLabel.text = objItem[@"brands"];

    }
}

objectTitlesArray 是我单独制作的数组，其中包含返回的对象的名称，因此我可以轻松获取名称。

这是 resultsArray 中的内容:

<__NSArrayI 0x8cb9900>(
{
asins =     (
);
"best_page" =     {
    currency = USD;
    deeplink = "http://www.textbooks.com/iPhone-Book-Covers-iPhone-4S-iPhone-4-and-iPhone-3GS/9780321832764/Scott-Kelby.php";
    description = "\"Excellent Marketplace listings for \"\"iPhone Book: Covers iPhone 4S, iPhone 4, and iPhone 3GS\"\" by Scott Kelby starting as low as $1.99!\"";
    "image_url" = "http://images.textbooks.com/TextbookInfo/Covers/0321832760.gif";
    "in_stock" = 1;
    "live_price_url" = "http://api.invisiblehand.co.uk/v1/pages/live_price?url=http%3A%2F%2Fwww.textbooks.com%2FiPhone-Book-Covers-iPhone-4S-iPhone-4-and-iPhone-3GS%2F9780321832764%2FScott-Kelby.php";
    "original_url" = "http://www.textbooks.com/iPhone-Book-Covers-iPhone-4S-iPhone-4-and-iPhone-3GS/9780321832764/Scott-Kelby.php";
    pnp = "3.99";
    price = "24.99";
    "price_confidence" = low;
    region = us;
    "retailer_name" = "Textbooks.com";
    title = "iPhone Book: Covers iPhone 4S, iPhone 4, and iPhone 3GS";
};
brands =     (
    Pearson
);
categories =     (
);
eans =     (
    9780321832764
);
id = 10a9fb4e3868f5289dc0d53af80ae86a;
"image_url" = "http://images.textbooks.com/TextbookInfo/Covers/0321832760.gif";
isbns =     (
    0321832760
);
models =     (
);
mpns =     (
    0321832760
);
"number_of_pages" = 1;
resource = "/products/10a9fb4e3868f5289dc0d53af80ae86a";
title = "iPhone Book: Covers iPhone 4S, iPhone 4, and iPhone 3GS";
upcs =     (
);
},

感谢所有帮助，并提前致谢。

编辑:

将我的代码更改为:

for (NSDictionary *objItem in resultsArray)
{
     NSString *currentItemName = [objectTitlesArray objectAtIndex:indexPath.row];

    if ([currentItemName isEqualToString:objItem[@"title"]])
    {
        if (cell.priceLabel.text != (id)[NSNull null] && cell.priceLabel.text.length != 0 && cell.brandLabel.text != (id)[NSNull null] && cell.brandLabel.text.length != 0)
        {


        cell.nameLabel.text = currentItemName;
        NSDictionary *bestPageDictionary = objItem[@"best_page"];
        cell.priceLabel.text = bestPageDictionary[@"price"];
        NSArray *brandsArray = objItem[@"brands"];
        cell.brandLabel.text = [brandsArray firstObject];
        }

    }
}

现在我得到 NSInvalidArgumentException'，原因:'-[__NSCFNumber 长度]:无法识别的选择器发送到实例 0x8c98c00'

Answer 1

您的字典结构与您试图从中获取的数据不匹配。

• brands 是数组，不是字符串。它恰好包含一个字符串元素，因此您只需要捕获它即可。

  NSArray *brandsArray = objItem[@"brands"];
  cell.brandLabel.text = [brandsArray firstObject];
  

• price 不在顶级字典中，而是嵌套在其中的另一个字典中。

  NSDictionary *bestPageDictionary = objItem[@"best_page"];
  cell.priceLabel.text = bestPageDictionary[@"price"];
  

编辑 看起来价格实际上可能是一个数字，尽管它看起来是一个字符串。试试这个:

NSDictionary *bestPageDictionary = objItem[@"best_page"];
NSNumber *price = bestPageDictionary[@"price"];
cell.priceLabel.text = [NSString stringWithFormat:@"%@", price];