Passing an instance with list to an API - asp.net

Question

There is the complete code of the test.
When posting JSON data to the API, the instance person is null.
Can any one tell me why
Model
public class Diploma
{
public int PeronId { get; set; }
public string Tile { get; set; }
public string Organism { get; set; }
}
public class Person
{
public int Id { get; set; }
public string Name { get; set; }
public string Function { get; set; }
public List<Diploma> Diplomas { get; set; }
public Person()
{
Diplomas = new List<Diploma>();
}
}
Controller
public class PersonnesController : ApiController
{
private const string cs = "Data Source=.;Initial Catalog=test;Integrated Security=True";
// POST : Person
[HttpPost]
public int Post([FromBody] Person person)
{
bool res = false;
int id;
SqlCommand cmd = new SqlCommand();
using (SqlConnection connection = new SqlConnection(cs))
{
cmd = new SqlCommand("insert dbo.personnes (Name, Function) output INSERTED.ID values (#name, #function)", connection);
cmd.Parameters.AddWithValue("#nam", person.Name);
cmd.Parameters.AddWithValue("#function", person.Function);
connection.Open();
id = (int)cmd.ExecuteScalar();
foreach (Diploma diploma in person.Diplomas)
{
cmd = new SqlCommand("insert diplomes values(#id, #title, #organism)", connection);
cmd.Parameters.AddWithValue("#id", id);
cmd.Parameters.AddWithValue("#title", diploma.Tile);
cmd.Parameters.AddWithValue("#organism", diploma.Organism);
cmd.ExecuteNonQuery();
}
return id;
}
}
}
I'm testing with RESTClient for Firefox,
In header section:
Content-type : application/x-www-form-urlencoded

Answer 1

The data is being sent using the wrong Content-Type.
It was indicated that data was sent using Content-type : application/x-www-form-urlencoded
while the shown data is JSON
{ "Name": "my name", "Function": "my function", "diplomas": [{ "title": "diploma 1", "organism": "university 1" }, { "title": "diploma 2", "organism": "university 2" }] }
which would use Content-type : application/json content type
The model binder was unable to parse the content using the provided content type, so it default the model to null.