Using Linq to Get List of Strings from Json

Question

I've got this JSON (below) and I'm having trouble selecting a list of string that would be "MARYLAND", "NEW YORK", "PENNSYLVANIA".

    {
  "displayFieldName": "NAME",
  "fieldAliases": {
    "STATE": "STATE"
  },
  "fields": [
    {
      "name": "STATE",
      "type": "esriFieldTypeString",
      "alias": "STATE",
      "length": 20
    }
  ],
  "features": [
    {
      "attributes": {
        "STATE": "Maryland"
      }
    },
    {
      "attributes": {
        "STATE": "New York"
      }
    },
    {
      "attributes": {
        "STATE": "Pennsylvania"
      }
    }
  ]
}

So far I'm getting the json string and deserializing it to a JObject and I can see the children. I'm having trouble going much further with it though and it doesn't fit with may other examples I've seen because the "features" are a collection of "attributes". I'm having trouble writing the linq to get down to the next level.

Here's my code:

            var foo = response.Content.ReadAsStringAsync().Result;

            var json = (JObject)JsonConvert.DeserializeObject(foo);

            var cf = json["features"].Children();

Can anybody help me with the linq statement to get the string of states from this?

Thanks

Answer 1

Assuming your JObject class looks somehow like in the sample below, you could do the following:

string[] states = json.features.SelectMany(f => f.attributes).ToArray();

This yields a single array with the three entries Maryland, New York and Pennsylvania.

Full sample:

class JObject
{
    public Feature[] Features { get; set; }
}

class Feature
{
    public string[] Attributes { get; set; }
}

class Program
{
    static void Main(string[] args)
    {
        Feature f1 = new Feature { Attributes = new[] { "Maryland" } };
        Feature f2 = new Feature { Attributes = new[] { "New York" } };
        Feature f3 = new Feature { Attributes = new[] { "Pennsylvania" } };

        JObject state = new JObject
        {
            Features = new[] { f1, f2, f3 }
        };

        string[] states = state.Features.SelectMany(f => f.Attributes).ToArray();
    }
}