C# deserialize Json unknown keys

Question

I have this JSON and i have to deserialize it:

{
  "homepage": "http://files.minecraftforge.net/maven/net/minecraftforge/forge/",
  "promos": {
    "1.10-latest": "12.18.0.2000",
    "1.10.2-latest": "12.18.1.2014",
    "1.10.2-recommended": "12.18.1.2011",
    "1.5.2-latest": "7.8.1.738",
    "1.5.2-recommended": "7.8.1.737",
    "1.6.1-latest": "8.9.0.775",
    "1.6.2-latest": "9.10.1.871",
    "1.6.2-recommended": "9.10.1.871",
    "1.6.3-latest": "9.11.0.878",
    "1.6.4-latest": "9.11.1.1345",
    "1.6.4-recommended": "9.11.1.1345",
    "1.7.10-latest": "10.13.4.1614",
    "1.7.10-latest-1.7.10": "10.13.2.1343",
    "1.7.10-recommended": "10.13.4.1558",
    "1.7.2-latest": "10.12.2.1147",
    "1.7.2-recommended": "10.12.2.1121",
    "1.8-latest": "11.14.4.1577",
    "1.8-recommended": "11.14.4.1563",
    "1.8.8-latest": "11.15.0.1655",
    "1.8.9-latest": "11.15.1.1902",
    "1.8.9-recommended": "11.15.1.1722",
    "1.9-latest": "12.16.0.1942",
    "1.9-recommended": "12.16.1.1887",
    "1.9.4-latest": "12.17.0.1990",
    "1.9.4-recommended": "12.17.0.1976",
    "latest": "12.18.1.2014",
    "latest-1.7.10": "10.13.2.1343",
    "recommended": "12.18.1.2011"
  }
}

Searching on this website a lot, i came out with this code:

dynamic json = JsonConvert.DeserializeObject<Dictionary<string, string>>(data);
foreach (KeyValuePair<string, string> entry in json["promos"])
{
    MessageBox.Show(entry.Key);
    MessageBox.Show(entry.Value);
}

I need to get both Key and Value from that Json but with this code it says there is an unexpected character on line 3 pos 13. I tried in a lot of different ways but i can't get value and key at the same time. With some code i got just the key and with some other code i got just the value. Can you explain me how to obtain both value and key?

score 9 · Accepted Answer · answered Jul 16 '16 at 14:00

You can directly parse the json as JObject and convert the node "promos" to Dictionary

var json = JObject.Parse(data);
var promos = json["promos"].ToObject<Dictionary<string, string>>();
foreach (var entry in promos)
{
    MessageBox.Show(entry.Key);
    MessageBox.Show(entry.Value);
}

Tommaso Scalici · Answer 2 · 2016-07-16T13:53:57.710

The issue is the type you're trying to deserialize into. You're trying to deserialize it as a Dictionary, but while the first entry is a pair of string, promos is a Dictionary itself, so you can't cast the value of "promos" to string! Supposing your json is in a file called "json.json" you can obtain a Dictionary by iterating through promos JObject and cast the items you obtain to a JProperty, in this way:

var json = File.ReadAllText("json.json");
var deserialized = JsonConvert.DeserializeObject<JObject>(json);

var dictionary = new Dictionary<string, string>();

foreach (JProperty item in deserialized["promos"])
    dictionary.Add(item.Name, item.Value.ToString());

derpirscher · Answer 3 · 2016-07-16T13:56:00.463

1

Your data is not a Dictionary<string, string> because the value of promos is not a string but a Dictionary.

You could deserialize to an JObject and then get the value of your promos property.

JObject json = JsonConvert.DeserializeObject<JObject>(data);
//var promos = json.Value<Dictionary<string, string>>("promos");
var promos = data["promos"].ToObject<Dictionary<string, string>>();
foreach (KeyValuePair<string, string> entry in promos) {
   //do some stuff
}

EDIT

Not sure, why the original way does not work and don't have the time right now to investigate, but the second line should do it.

edited Jul 16 '16 at 13:56

answered Jul 16 '16 at 13:35

derpirscher

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It says System.InvalidCastException: Cannot cast newtonsoft.json.linq.jobject into newtonsoft.json.linq.jtoken. What does it mean? How can i solve it? – ThePHPAddicted Jul 16 '16 at 13:39

C# deserialize Json unknown keys

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