If you are using .NET 3.5 or above, you can use the DataContractJsonSerializer class (specifically the ReadObject method). Suppose you had a class that looks like this:
[DataContract]
public class Token
{
[DataMember(Name="TokenId")]
public string TokenId { get; set; }
[DataMember(Name="TokenSecret")]
public string TokenSecret { get; set; }
}
To deserialize the JSON into this structure, you'd use
Token token = new Token();
var serializer = new System.Runtime.Serialization.Json.DataContractJsonSerializer();
using (MemoryStream ms = new MemoryStream(Encoding.Unicode.GetBytes(json))
{
token = serializer.ReadObject(ms) as Token;
}