Send List of Objects to my wcf web service

Question

Good staff,

I need to create a Web service WCF which receives a list of objects and inserts it into a database postgresql. To test created a client app Vb.net, but something is not going as expected.

So far I have implemented the following condition:

Iservice.Cs

  public interface IService1
   {
    [OperationContract]
    int InsertClients(MyListofClients clients);
   }

  [DataContract]
  public class MyListofClients
  {

    [DataMember]
    List<Client> Clients { get; set; }

  }

[DataContract]
public class Client
{
    [DataMember]
    public string clientId { get; set; }

    [DataMember]
    public string ClientName { get; set; }

    [DataMember]
    public List<Client> Clients { get; set; }
}
}  

Servic1.svc

 public int InsertClients(MyListofClients clients)
  {
    int res, result;
    using (NpgsqlConnection conn = new NpgsqlConnection(connStringFarm))
    {
        conn.Open();
        List<MyListofClients> firstStringList = new       List<MyListofClients>();
        string cmdStr = String.Format("Insert Into table (x1,x2)" +
                                       " VALUES(@x1,@x2)");

        foreach (var item in firstStringList)
        {
            NpgsqlCommand cmd = new NpgsqlCommand(cmdStr, conn);
            result = cmd.ExecuteNonQuery();
        }

        conn.Close();
        return 0;
       }

App Client

  Private Sub Button1_Click(sender As Object, e As EventArgs) Handles          Button1.Click
    Dim db_comm As New NpgsqlCommand
    Dim Reader As NpgsqlDataReader


    Dim query As String = "Select code1,name1 from clientes"
    db_comm.CommandText = query
    db_comm.Connection = conn
    conn.open
    Reader = db_comm.ExecuteReader

    Dim list As New List(Of String)

    While Reader.Read
            list.Add(Reader.GetString("code1"))
            list.Add(Reader.GetString("name1"))
    End While

    Dim API As APICS.Service1Client = New APICS.Service1Client()
    API.InsertClientsAsync(list)
End Sub

ERROR Value of type 'List(Of String)' cannot be converted to 'Mylistofclients'.

I think the problem has to do with list that has to be like 'Mylistofclients'.

Dim list As New List(Of APICS.MyListofClients)

however I can not understand how I should send the list this way

Any hint??

Answer 1

CS, I advise you to generate the Webservice proxy using the "Add Service Reference..." option that appears when right-clicking on "References".

try to use a "Metadata Exchange" endpoint when downloading service information, this approach is preferable to using the good old ?wsdl.

if configured this way, your client application would not even allow sending a list of strings instead of a client list.

now try to change your call to the following.:

Dim list As New List(Of APICS.Client)

While Reader.Read
        Dim cliente As APICS.Client = New APICS.Client()
        cliente.clientId = Reader.GetString("code1"))
        cliente.ClientName = Reader.GetString("name1"))
        list.Add(cliente)
End While

remember that I am not a VB.NET programmer, so the above code may present some basic (syntax) errors, but its logic remains the same.