Deserialization of JSON

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I’m having a hard time deserializing this JSON:

  string json = "{\"Cidade\":[\"Arrio do Sal\",\"Atl\\u00e2ntida\",\"Bom Princ\\u00edpio\",\"Brochier\",\"Cachoeirinha\",\"Canaos\",\"Canela\",\"Canoas\",\"Cap\\u00e3o da Canoa\",\"Cidreira\",\"Distrito Morungava\",\"Eldorado Do Sul\",\"Esteio\",\"Florian\\u00f3polis\",\"Governador Celso De Ramos\",\"Gramado\",\"Gravata\\u00ed\",\"Gua\\u00edba\",\"Imb\\u00e9\",\"Ivoti\",\"Montenegro\",\"Nova Petr\\u00f3polis\",\"Nova Santa Rita\",\"Nova Tramanda\\u00ed\",\"Novo Hamburgo\",\"Os\\u00f3rio\",\"Pinhal\",\"Porto Alegre\",\"S\\u00e3o Francisco De Paula\",\"S\\u00e3o jos\\u00e9 do Herval\",\"S\\u00e3o Leopoldo\",\"Sapucaia Do Sul\",\"Terra De Areia\",\"Torres\",\"Tramanda\\u00ed\",\"Triunfo\",\"Viam\\u00e3o\"]}";

I have tried several ways using the Newtonsoft library.

I created a class Cidade to deserialize on an object, I created a class Cidadeitem which is a List of class objects Cidade, I tried to deserialize in a List<String>, tried with Dictionary, all without success. The error reported is this:

Newtonsoft.Json.Jsonserializationexception: 'Cannot deserialize the Current JSON Object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[Apivistaconsole.Cidadeitens]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.

To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal . NET type (e.g. not a Primitive type like integer, not a Collection type like an array or List) that can be deserialized from a JSON Object.

Jsonobjectattribute can also be Added to the type to force it to deserialize from a JSON Object. Path 'City', line 1, position 10.'

I put the JSON return right here to facilitate, but I can put the method I use to call the REST if it will help clarify. I’ve been able to deserialize other more complex JSON structures, but this string-only array isn’t really working.

c# json .net rest

  • in fact your class would need to own a property string[] Cidade. Include your model and the code you’re using for the deserialization.

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3 answers

1

Simple, your object has a list of cities, so it looks like this.

using System.Collections.Generic;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string json = "{\"Cidade\":[\"Arrio do Sal\",\"Atl\\u00e2ntida\",\"Bom Princ\\u00edpio\",\"Brochier\",\"Cachoeirinha\",\"Canaos\",\"Canela\",\"Canoas\",\"Cap\\u00e3o da Canoa\",\"Cidreira\",\"Distrito Morungava\",\"Eldorado Do Sul\",\"Esteio\",\"Florian\\u00f3polis\",\"Governador Celso De Ramos\",\"Gramado\",\"Gravata\\u00ed\",\"Gua\\u00edba\",\"Imb\\u00e9\",\"Ivoti\",\"Montenegro\",\"Nova Petr\\u00f3polis\",\"Nova Santa Rita\",\"Nova Tramanda\\u00ed\",\"Novo Hamburgo\",\"Os\\u00f3rio\",\"Pinhal\",\"Porto Alegre\",\"S\\u00e3o Francisco De Paula\",\"S\\u00e3o jos\\u00e9 do Herval\",\"S\\u00e3o Leopoldo\",\"Sapucaia Do Sul\",\"Terra De Areia\",\"Torres\",\"Tramanda\\u00ed\",\"Triunfo\",\"Viam\\u00e3o\"]}";
            RootObject rootObject = Newtonsoft.Json.JsonConvert.DeserializeObject<RootObject>(json);

            var teste = rootObject.Cidade;
        }
    }


    public class RootObject
    {
        public List<string> Cidade { get; set; }
    }
}

1

The example you showed does not represent an object Cidade who owns a property CidadeItem of the kind List<string>.

It is actually an object that owns a property Cidade which can be a Ienumerable or even a string[].

class ExemploModel
{
    public IEnumerable<string> Cidade { get; set; }
}

Now yes deserialize will work:

string json = "{\"Cidade\":[\"Arrio do Sal\",\"Atl\\u00e2ntida\",\"Bom Princ\\u00edpio\",\"Brochier\"]}"; //...

var listaCidades = JsonConvert.DeserializeObject<ExemploModel>(json);

1

I did in cosoleApplication and it worked

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Stack
{
class Program
{
    public List<string> Cidade { get; set; }
    static void Main(string[] args)
    {
        string json = "{\"Cidade\":[\"Arrio do Sal\",\"Atl\\u00e2ntida\",\"Bom Princ\\u00edpio\",\"Brochier\",\"Cachoeirinha\",\"Canaos\",\"Canela\",\"Canoas\",\"Cap\\u00e3o da Canoa\",\"Cidreira\",\"Distrito Morungava\",\"Eldorado Do Sul\",\"Esteio\",\"Florian\\u00f3polis\",\"Governador Celso De Ramos\",\"Gramado\",\"Gravata\\u00ed\",\"Gua\\u00edba\",\"Imb\\u00e9\",\"Ivoti\",\"Montenegro\",\"Nova Petr\\u00f3polis\",\"Nova Santa Rita\",\"Nova Tramanda\\u00ed\",\"Novo Hamburgo\",\"Os\\u00f3rio\",\"Pinhal\",\"Porto Alegre\",\"S\\u00e3o Francisco De Paula\",\"S\\u00e3o jos\\u00e9 do Herval\",\"S\\u00e3o Leopoldo\",\"Sapucaia Do Sul\",\"Terra De Areia\",\"Torres\",\"Tramanda\\u00ed\",\"Triunfo\",\"Viam\\u00e3o\"]}";

        Cidade cidades = JsonConvert.DeserializeObject<Cidade>(json);
    }
}
}

  • You have created a City class or just the property?

  • For the test I created only the property. )

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