Question

我在尝试访问JSON字典中的字符串时遇到问题，这是JSON数据，我正在尝试访问的字符串是“链接”值：

channels =     (
  {
    social =             {
      facebook =                 {
        "facebook_id" = 47360808996;
        link = "https://www.facebook.com/CBS";
      };
      twitter =                 {
        link = "https://twitter.com/CBS";
        "twitter_id" = 97739866;
      };
    };
  }
);

这是我创建的自定义对象，它不断给我一个错误

“Type”（键：字符串，值：AnyObject）'没有下标成员“

class SocialInfo: NSObject, Mappable {
  var facebook: String?
  var facebookDict: String?

  required init?(map: Map) {
  }

  func mapping(map: Map) {

    ///transforms string to dictionary [string: anyobject] - only used for specific JSON data name: (facebook) - (link)
    let facebookTransform = TransformOf<String, [String: AnyObject]> (fromJSON: { (value: [String: AnyObject]?) -> String? in
      if let value = value {
        for dict in value {
          if let social = dict["social"] as? NSDictionary {
          if let fb = social["facebook"] as? [String: AnyObject]{
            if let fbLink = fb["link"] as? String{
              return fbLink
            }
          }
        }
      }
      }
      return nil
    }, toJSON: { (value: String?) -> [String: AnyObject]? in
      return nil
    })

   facebookDict <- (map["channels"], facebookTransform)
    facebook <- map["link"]
  }
}

这是我的JSON调用函数来获取信息：

  func getSocialInfo (_ completion: (([SocialInfo]) -> Void)?) {

    Alamofire.request("\(baseURL)/\(apiKey)/show/950", method: .get, encoding: JSONEncoding.default).responseArray { (response: DataResponse<[SocialInfo]>) in

        if let channelsResponse = response.result.value {

         completion?(channelsResponse)

    }
  }
}

作为参考，我使用NSURLSession从一个工作项目中重新创建了这个，下面的代码可以工作：

  if let channels = jsonResult["channels"] as? [[String:AnyObject]], !channels.isEmpty {
        let channel = channels[0] // now the compiler knows it's [String:AnyObject]
        let social = channel["social"] as? NSDictionary
        let facebookDict = social!["facebook"] as? [String:AnyObject]
        let facebook = nullToNil(facebookDict!["link"]) as? String ?? "N/A"
        let twitterDict = social!["twitter"] as? [String:AnyObject]
        let twitter = nullToNil(twitterDict!["link"]) as? String ?? "N/A"

Answer 1

我假设您使用Swift 3，因为Swift 2已被弃用。

在Swift 3中解析JSON时，应该避免使用NSDictionary和AnyObject。只需在任何地方使用[String: Any]。

如何使用Alamofire / ObjectMapper返回嵌入在字典中的JSON字符串？

1 个答案: