how To disable textbox inside gridview

 Private Sub grdUserReport_RowDataBound(sender As Object, e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles grdUserReport.RowDataBound

        For Each row As GridViewRow In grdUserReport.Rows

            If row.RowType = DataControlRowType.DataRow Then

                For i As Integer = 1 To row.Cells.Count - 1

                    If row.Cells(i).Controls.OfType(Of TextBox)().ToList().Count > 0 Then

                        ' row.Cells(i).Controls.OfType(Of TextBox)().FirstOrDefault().Visible = isChecked

                        row.Cells(i).Controls.OfType(Of TextBox)().FirstOrDefault().Enabled = True

                    End If

                    Dim country As String = TryCast(row.Cells(0).FindControl("litType"), Label).Text

                    Dim strColumn As String = DataBinder.Eval(e.Row.DataItem, "ControlScr").ToString

                    ' Dim check As String = TryCast(row.Cells(1).FindControl("litStatus"), Label).Text

                    ' Dim txtForboy As String = TryCast(row.Cells(0).FindControl("QTotal"), Literal).Text

                    Dim txtBoxMen As TextBox = TryCast(grdUserReport.HeaderRow.FindControl("QTotal"), TextBox)

                    If country.Trim() = "DQTwoValueInteger.ascx" Then

                        txtBoxMen.Enabled = False

                        row.Cells(1).Controls.OfType(Of TextBox)().FirstOrDefault().Enabled = False

                        row.Cells(9).Controls.OfType(Of TextBox)().FirstOrDefault().Enabled = False

                        row.Cells(10).Controls.OfType(Of TextBox)().FirstOrDefault().Enabled = False

                        row.Cells(6).Controls.OfType(Of TextBox)().FirstOrDefault().Enabled = False

                    End If

                Next

            End If

        Next

    End Sub