47

I have a json block like this:

{
    "ADDRESS_MAP":{

        "ADDRESS_LOCATION":{
            "type":"separator",
            "name":"Address",
            "value":"",
            "FieldID":40
        },
        "LOCATION":{
            "type":"locations",
            "name":"Location",
            "keyword":{
                "1":"LOCATION1"
            },
            "value":{
                "1":"United States"
            },
            "FieldID":41
        },
        "FLOOR_NUMBER":{
            "type":"number",
            "name":"Floor Number",
            "value":"0",
            "FieldID":55
        },
        "self":{
            "id":"2",
            "name":"Address Map"
        }
    }
}

How can I get all the key items that this token includes. For example from the above code I want to have "ADRESS_LOCATION" , "LOCATION", "FLOOR_NUMBER" and "self".

Luke Girvin
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Husein Behboudi Rad
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3 Answers3

69

You can cast your JToken to a JObject and then use the Properties() method to get a list of the object properties. From there, you can get the names rather easily.

Something like this:

string json =
@"{
    ""ADDRESS_MAP"":{

        ""ADDRESS_LOCATION"":{
            ""type"":""separator"",
            ""name"":""Address"",
            ""value"":"""",
            ""FieldID"":40
        },
        ""LOCATION"":{
            ""type"":""locations"",
            ""name"":""Location"",
            ""keyword"":{
                ""1"":""LOCATION1""
            },
            ""value"":{
                ""1"":""United States""
            },
            ""FieldID"":41
        },
        ""FLOOR_NUMBER"":{
            ""type"":""number"",
            ""name"":""Floor Number"",
            ""value"":""0"",
            ""FieldID"":55
        },
        ""self"":{
            ""id"":""2"",
            ""name"":""Address Map""
        }
    }
}";

JToken outer = JToken.Parse(json);
JObject inner = outer["ADDRESS_MAP"].Value<JObject>();

List<string> keys = inner.Properties().Select(p => p.Name).ToList();

foreach (string k in keys)
{
    Console.WriteLine(k);
}

Output:

ADDRESS_LOCATION
LOCATION
FLOOR_NUMBER
self
Brian Rogers
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  • Iterating over the JObject containers instead of converting to .NET types results in less code and probably better performance. I've added an answer to complement this one that shows that approach. – Ian Jul 07 '16 at 19:42
  • Or - if you know what property you want to: var location = inner.Property("LOCATION").Value; – simaglei Oct 01 '20 at 09:17
47

In addition to the accepted answer I would like to give an answer that shows how to iterate directly over the Newtonsoft collections. It uses less code and I'm guessing its more efficient as it doesn't involve converting the collections.

using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
//Parse the data
JObject my_obj = JsonConvert.DeserializeObject<JObject>(your_json);

foreach (KeyValuePair<string, JToken> sub_obj in (JObject)my_obj["ADDRESS_MAP"])
{
    Console.WriteLine(sub_obj.Key);
}

I started doing this myself because JsonConvert automatically deserializes nested objects as JToken (which are JObject, JValue, or JArray underneath I think).

I think the parsing works according to the following principles:

  • Every object is abstracted as a JToken

  • Cast to JObject where you expect a Dictionary

  • Cast to JValue if the JToken represents a terminal node and is a value

  • Cast to JArray if its an array

  • JValue.Value gives you the .NET type you need

AdamC
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Ian
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3

If you know the structure of the json that you're receiving then I'd suggest having a class structure that mirrors what you're receiving in json.

Then you can call its something like this...

AddressMap addressMap = JsonConvert.DeserializeObject<AddressMap>(json);

(Where json is a string containing the json in question)

If you don't know the format of the json you've receiving then it gets a bit more complicated and you'd probably need to manually parse it.

check out http://www.hanselman.com/blog/NuGetPackageOfTheWeek4DeserializingJSONWithJsonNET.aspx for more info

James Sinclair
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