Llenar DataGridView – VB.net

    Public Function consultarData(Optional xFlag As Integer = 1,
                                  Optional ByVal xCriterio As String = "") As DataTable
        Try
            conectado()
            cmd = New SqlCommand("[paAviMesaConsultar]")
            cmd.CommandType = CommandType.StoredProcedure
            cmd.Connection = cnn

            With cmd
                .Parameters.AddWithValue("@xFlag", Trim(xFlag))
                .Parameters.AddWithValue("@xCriterio", Trim(xCriterio))
            End With

            If cmd.ExecuteNonQuery Then
                Dim dt As New DataTable
                Dim da As New SqlDataAdapter(cmd)
                da.Fill(dt)
                Return dt
            Else
                Return Nothing
            End If

        Catch ex As Exception
            Return Nothing
        Finally
            desconectado()
        End Try
    End Function

    'Metodo para Cargar registros en el DataGrid
    Private Sub llenarGrid(Filtrar As Boolean)
        Try
            dt = dta.consultarData(2, txtFiltrar.Text) '

            If dt.Rows.Count <> 0 Then 'Verifica Si el Dt tiene registros
                dgListado.DataSource = dt 'Llenar el DataGrid 
            Else
               dgListado.DataSource = Nothing
            End If

        Catch ex As Exception
            sistemaError(ex.Message)
        End Try
    End Sub