public class Test
    {

        public int total;

        public int count;

        public OpenIdType data;

        public String next_openid;
    }

     public class OpenIdType
     {
         public List<string> openid;
     }
    class Program
    {
        static void Main(string[] args)
        {
            string str="{ \"total\": 2, \"count\": 2, \"data\": { \"openid\": [ \"\", \"OPENID1\", \"OPENID2\", \"OPENID3\"] }, \"next_openid\": \"NEXT_OPENID\" }";

            Test test=JsonHelp.JsonDeserialize<Test>(str);
        }
    }

    public class JsonHelp
    {

        public static string JsonSerializer<T>(T t)
        {
            JavaScriptSerializer jsonSerialize = new JavaScriptSerializer();
            return jsonSerialize.Serialize(t);
        }
        public static T JsonDeserialize<T>(string jsonString)
        {
            JavaScriptSerializer jsonSerialize = new JavaScriptSerializer();
            return (T)jsonSerialize.Deserialize<T>(jsonString);
        }
    }