如何创建这个json模型，c#

如何为这个json创建模型?

{"代码":"1","消息":"OK","响应":{"用户":{" id ": " 124 "、"usertype":"29"、"currenttime":"2013 - 04 - 24 - t08:09:20.487 + 00:00"、"sessionid":"2 bcf1c92 - 9 - b97 - 47 - d8 - 8995"b39cf7cbe2af}}}

我写的

:

public class BaseResponse
    {
        public bool success;
        public String message;
    }
    public class CreateTaskResponse : BaseResponse
    {
        CreateTaskResponseData data = new CreateTaskResponseData();
        public User getUser()
        {
            return data.getUser();
        }
    }
    class CreateTaskResponseData
    {
        User user = new User();
        public User getUser()
        {
            return user;
        }
    }
public class User
{
    public int id;
    public int usertype;
    public string currenttime;
    public string sessionid;
}

和解析:

CreateTaskResponse Login = SimpleDataSerializer.ToObject<CreateTaskResponse>(response);

错误:Login.getUser()。Sessionid为空

public class User
{
    public string id { get; set; }
    public string usertype { get; set; }
    public string currenttime { get; set; }
    public string sessionid { get; set; }
}
public class Response
{
    public User user { get; set; }
}
public class RootObject
{
    public string code { get; set; }
    public string message { get; set; }
    public Response response { get; set; }
}

var obj = JsonConvert.DeserializeObject<RootObject>(json);