Not Getting the Root Name in JSON Format using WCF Rest - json

Question

I am not getting any root value of the Json Format.
I am getting the response as follows:
[{"Username":"demo","UserID":8,"Password":"demo","EmaiID":"demo#gmail.com"}]
I would like to have the format as follows
{UserList: [[{"Username":"demo","UserID":8,"Password":"demo","EmaiID":"demo#gmail.com"}]}
Service Declaration :
public interface IDemo
{
[OperationContract]
[WebInvoke(RequestFormat = WebMessageFormat.Json,ResponseFormat =
WebMessageFormat.Json, BodyStyle = WebMessageBodyStyle.Bare,
UriTemplate = "/Validate", Method = "POST")]
Stream ValidateUser(Login obj);
}
[DataContract]
public class Login
{
public Login()
{
}
[DataMember]
public string Username { get; set; }
[DataMember]
public string Password { get; set; }
}
Service Definition :
public class Demo: IDemo
{
string Json = string.Empty;
JavaScriptSerializer obj1 = new JavaScriptSerializer();
public Stream ValidateUser(Login obj)
{
UserList objUserList = new UserList();
Users objUser = new Users();
objUser.Username = obj.Username;
objUser.Password = obj.Password;
objUserList = LoginDataService.ValidateUser(objUser.Username,objUser.Password) ;
if (objUserList.Count > 0)
{
Json = obj1.Serialize(objUserList);
WebOperationContext.Current.OutgoingResponse.ContentType =
"application/json; charset=utf-8";
}
else
{
UserError objError = new UserError();
objError.ErrMsg = "LoginFailed";objError.Username = objUser.Username ;
Json = obj1.Serialize(objError);
WebOperationContext.Current.OutgoingResponse.ContentType =
"application/json; charset=utf-8";
}
return new MemoryStream(Encoding.UTF8.GetBytes(Json));
}
}
Can anyone help me to get the result with root element and let me know what kind of mistake i have done.
Thanks & Regards,
Vijay

Answer 1

You are getting the format like that since you are serializing a collection into JSON. You can return a class that wraps the list inside as a property then you will get what you desire.
For ex. you can create a class like this
public class UserListResponse
{
public UserList UserList{get; set;}
}
Now you get the JSON as what you expected, like
{UserList:[..]}
I don't understand why you are returning a Stream and doing yourself all the serialization framework, basically this all done by the framework. All you have to do is return the wrapper class UserListResponse from the service method.
public class Demo: IDemo
{
public UserListResponse ValidateUser(Login obj)
{
...
return new UserListResponse{ UserList = objUserList};
}
}
The WCF will take care of returning the structure into JSON or XML and you don't need to worry about that.

Answer 2

While the above solution perfectly works you can also try using paramter BodyStyle=WebMessageBodyStyle.WrappedResponse of WebInvoke attribute on your method.
This wraps the values in type name.