ios - JSON key :value pairs disappearing after original json call

Question

我一直在尝试使用 Swift 从 JSON 读取数据，但在原始 json 调用后它一直不起作用。这是我的有效代码:

func loadUrl(url:String){
    DispatchQueue.global().async {
        do {
            let appUrl = URL(string:url)!
            let data = try Data(contentsOf:appUrl)
            let json = try JSONSerialization.jsonObject(with: data) as! [String:Any]
            DispatchQueue.main.async {
                print(json)
            }
        } catch {
            DispatchQueue.main.async {
                print("Cannot connect to the server.")
            }
        }
    }
}

它打印这个结果:

["results": <__NSSingleObjectArrayI 0x60000000ae80>(
    {
        "address_components" =     (
                {
            "long_name" = Brooklyn;
            "short_name" = Brooklyn;
            types =             (
                political,
                sublocality,
                "sublocality_level_1"
            );
        },
                {
            "long_name" = "New York";
            "short_name" = "New York";
            types =             (
                locality,
                political
            );
        },
                {
            "long_name" = "Kings County";
            "short_name" = "Kings County";
            types =             (
                "administrative_area_level_2",
                political
            );
        },
                {
            "long_name" = "New York";
            "short_name" = NY;
            types =             (
                "administrative_area_level_1",
                political
            );
        },
                {
            "long_name" = "United States";
            "short_name" = US;
            types =             (
                country,
                political
            );
        }
    );
    "formatted_address" = "Brooklyn, NY, USA";
    geometry =     {
        bounds =         {
            northeast =             {
                lat = "40.739446";
                lng = "-73.83336509999999";
            };
            southwest =             {
                lat = "40.551042";
                lng = "-74.05663";
            };
        };
        location =         {
            lat = "40.6781784";
            lng = "-73.94415789999999";
        };
        "location_type" = APPROXIMATE;
        viewport =         {
            northeast =             {
                lat = "40.739446";
                lng = "-73.83336509999999";
            };
            southwest =             {
                lat = "40.551042";
                lng = "-74.05663";
            };
        };
    };
    "place_id" = ChIJCSF8lBZEwokRhngABHRcdoI;
    types =     (
        political,
        sublocality,
        "sublocality_level_1"
    );
}
)
, "status": OK]

但是，我想做的是一直到 formatted_address 键。然而，当我尝试这段代码时，程序崩溃了:

func loadUrl(url:String){
    DispatchQueue.global().async {
        do {
            let appUrl = URL(string:url)!
            let data = try Data(contentsOf:appUrl)
            let json = try JSONSerialization.jsonObject(with: data) as! [String:Any]
            let results = json["results"] as! [String:Any]
            DispatchQueue.main.async {
                print(results)
            }
        } catch {
            DispatchQueue.main.async {
                print("Cannot connect to the server.")
            }
        }
    }
}

有人知道如何解决这个问题吗？我唯一注意到的是结果的值(value)是:

<__NSSingleObjectArrayI 0x604000206d60>

我不知道这是什么。当我将相同的 json 放入在线查看器时，该值只是 0。这是为什么？ “results”的值不应该是address_components、formatted_address、geometry、place_id和types吗？

Answer 1

你可以试试吗

if let results = json["results"] as? [[String:Any]] {

   if let first = results[0] as? [String:Any] {
          print(first["formatted_address"])
   }
}