Programación Orientado a objetos con Visual Basic - Parte 2

Capa Presentación

Imports System.Data.SqlClient
Public Class UCvendedor
 
    Private Sub UCvendedor_Load(sender As Object, e As EventArgs) Handles Me.Load
        llenarCboVendedor()
    End Sub
    Private Sub llenarCbovendedor()
        Dim dtab As New DataTable
        Dim obj As New CapaNegocio.ClsCNmantenimiento
        dtab = obj.p_listaEmpleadoxcargo("03") ' 01 es el codigo de cargo de vendedor
        mostrarCbo(dtab, CboVendedor)
    End Sub
    Public ReadOnly Property idven() As String
        Get
            Return Me.CboVendedor.SelectedValue.ToString
        End Get
    End Property

End Class

Capa negocio

Public Function p_listaEmpleadoxcargo(wcar) As DataTable
        Return obj.p_listaempleadoxcargo(wcar)
End Function

Capa Data

Public Function p_listaempleadoxcargo(ByVal wcodcar As String) As DataTable
        Dim da As New SqlDataAdapter("Usp_lisEmpleadoxcargo", cnx.cn)
        da.SelectCommand.CommandType = CommandType.StoredProcedure
        'Parámetro para CodCargo
        Dim par As New SqlParameter("@codcar", SqlDbType.Char, 2)
        par.Direction = ParameterDirection.Input
        da.SelectCommand.Parameters.Add(par)
        par.Value = wcodcar
        'Rellena el DataTable dt
        da.Fill(dt)
        Return dt
  End Function

ClsConexion
Imports System.Data.SqlClient
Public Class ClsConexion
    Private _cn As New SqlConnection("Server=(Local);DataBase=BDElectro;Integrated security =False; user=sa;pwd=123qwe$;")
    'Propiedad de solo lectura
    Public ReadOnly Property cn() As SqlConnection
        Get
            Return _cn
        End Get
    End Property

End Class