How to add 'version' field to Content-Type Header in VB.NET

Question

I'm implementing communication with an API REST for my Visual Basic.Net application. The issue appears when I try to add the field version=1 to the Content-Type header. Here's the code I use in order to do it:

Public Function AddTercero(tercero As Tercero, connection As GestionaConnection) As Boolean
    If connection Is Nothing Then
        Throw New ArgumentNullException(NameOf(connection))
    End If
    If tercero Is Nothing Then
        Throw New ArgumentNullException(NameOf(tercero))
    End If

    Dim request = New HttpRequestMessage()
    request.RequestUri = New Uri(Convert.ToString(connection.RecursosDictionary("vnd.gestiona.thirds"), CultureInfo.CurrentCulture))
    request.Method = HttpMethod.Post
    request.Headers.Add("X-Gestiona-Access-Token", AccessToken)
    request.Headers.Add("Accept", "application/json")
    
    request.Content = New StringContent(JsonConvert.SerializeObject(tercero))
    request.Content.Headers.ContentType = New MediaTypeHeaderValue("application/vnd.gestiona.third+json; version=1") 
    Dim req = request.Content.ReadAsStringAsync

    Dim response As HttpResponseMessage = connection.Connection.SendAsync(request).Result
    request.Dispose()
    Dim resultado = response.Content.ReadAsStringAsync()
    Debug.WriteLine(resultado.Result.ToString)

    If response.StatusCode = HttpStatusCode.Created Then
        Return True
    ElseIf response.StatusCode = HttpStatusCode.Unauthorized Then
        Throw New InvalidOperationException("Error al añadir tercero: no tiene autorización " & response.ReasonPhrase)
    Else
        Throw New InvalidOperationException("Error al añadir tercero: " & response.StatusCode & " -> " & response.ReasonPhrase)
    End If
End Function

The error message says:

System.InvalidOperationException: Error al añadir tercero: 415 -> Unsupported Media Type

And the message I get from the server is:

 {
  "code": 415,
  "name": "Unsupported Media Type",
  "description": "Content not supported: application/vnd.gestiona.third+json",
  "technical_details": "http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.16"
}

I have spoken with the developers of the API and they say I must include the version field on the Content-Type header, here's what they said: Content-Type with version: application/vnd.gestiona.third+json; version=1 application/vnd.gestiona.third+json; version=1

Any ideas on how could I solve this problem?

Thank you for reading

Answer 1

I solved it by declaring the application/vnd.gestiona.third+json content type and the version=1 type separately as it follows:

request.Content.Headers.ContentType = New MediaTypeHeaderValue("application/vnd.gestiona.third+json")
request.Content.Headers.ContentType.Parameters.Add(New NameValueHeaderValue("version", "1"))

Instead of doing it as I was:

request.Content.Headers.ContentType = New MediaTypeHeaderValue("application/vnd.gestiona.third+json; version=1")

This way, it works as a charm.