I have this Class:

public class User
{
    public string id{ get; set; }
    public string name{ get; set; }
    public string password { get; set; }
    public string email { get; set; }
    public bool is_broker { get; set; }
    public string branch_id { get; set; }
    public string created_at{get; set;}
    public string updated_at{get; set;}
    public UserGroup UserGroup {get;set;}
    public UserAddress UserAddress { get; set; }
    public List<UserContact> UserContact {get; set;}

    public User()
    {
        UserGroup = new UserGroup();
        UserAddress = new UserAddress();
        UserContact = new List<UserContact>();
    }
}

I like to Serealize Only properties , how i block serealization of UserGroup, UserAdress, asn UserContact???

This is my Serealization function:

    public static string Serealize<T>(T obj)
    {
        System.Runtime.Serialization.Json.DataContractJsonSerializer serializer = new System.Runtime.Serialization.Json.DataContractJsonSerializer(obj.GetType());
        MemoryStream ms = new MemoryStream();
        serializer.WriteObject(ms, obj);
        return Encoding.UTF8.GetString(ms.ToArray(), 0,(int)ms.Length);
    }