You really should use an established library, such as Newtonsoft.Json (which even Microsoft uses for frameworks such as MVC and WebAPI), or .NET’s built-in JavascriptSerializer.
Here’s a sample of reading JSON using Newtonsoft.Json:
JObject o1 = JObject.Parse(File.ReadAllText(@"c:\videogames.json"));
// read JSON directly from a file
using (StreamReader file = File.OpenText(@"c:\videogames.json"))
using (JsonTextReader reader = new JsonTextReader(file))
{
JObject o2 = (JObject) JToken.ReadFrom(reader);
}