Deserialize JSON string to Dictionary<string,object>

See mridula's answer for why you are getting null. But if you want to directly convert the json string to dictionary you can try following code snippet.

    Dictionary<string, object> values = 
JsonConvert.DeserializeObject<Dictionary<string, object>>(json);

I like this method:

using Newtonsoft.Json.Linq;
//jsonString is your JSON-formatted string
JObject jsonObj = JObject.Parse(jsonString);
Dictionary<string, string> dictObj = jsonObj.ToObject<Dictionary<string, object>>();

You can now access anything you want using the dictObj as a dictionary. You can also use Dictionary<string, string> if you prefer to get the values as strings.

The MSDN documentation for the as keyword states that the statement expression as type is equivalent to the statement expression is type ? (type)expression : (type)null. If you run json.GetType() it will return System.Object[] and not System.Collections.Generic.Dictionary.

In cases like these where the type of object into which I want to deserialize a json object is complex, I use an API like Json.NET. You can write your own deserializer as:

class DictionaryConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        Throw(new NotImplementedException());            
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        // Your code to deserialize the json into a dictionary object.

    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        Throw(new NotImplementedException());   
    }
}

And then you can use this serializer to read the json into your dictionary object. Here's an example.