Question

I want to return a JSON from ASP.NET MVC ActionResult type method that looks something like this:

{
     success: true,
     users: [
    {id: 1, FileName: 'Text22'},
    {id: 2, FileName: 'Text23'}
    ]
}

How would I format it? Right now I have something like this

Return Json(New With {Key .success = "true", Key .users = responseJsonString}, JsonRequestBehavior.AllowGet)

Edit: I am using VB.NET but answers in C# are fine too.

Answer 1

I prefer using ViewModels, rather than manually constructing complex JSON responses. It ensures consistency against all methods that return the data, and is easier to work with strongly typed properties IMHO.

public class Response
{
    public bool Success { get; set; }
    public IEnumerable<User> Users { get; set; }
}

public class User 
{
    public int Id { get; set; }
    public string Name { get; set; }
}

and then just:

Response response = new Response();
response.Success = true;
// populate the rest of the data

return Json(response);

This also has the advantage of letting you use a base class for every response, if there’s common data like a success status, or error messages.

public class ResponseBase
{
    public bool Success { get; set; }
    public string Message { get; set; }
}

public class UserResponse : ResponseBase
{ 
    IENumerable<User> Users { get; set }
}

Now, if you have an error:

return Json(new ResponseBase() { Success = false, Message = "your error" });

or if it succeeds

return Json(new UserResponse() { Success = true, Users = users });

If you want to manually craft the JSON, then just:

return Json(new { success = true, users = new[] { new { id = 1, Name = "Alice"}, new { id = 2, Name = "Bob"} } });