How to auto generate SN on Grideview

below code shows how to do that.

Just you need to pass your datagridview in below function and it will generate auto number to Header cell.

NOTE: First you have to bind the datagridview with data then call the below function.

Public Sub AutoNumberRowsForGridView(ByVal dataGridView As DataGridView)

    If dataGridView IsNot Nothing Then

    Dim count As Integer = 0

    While (count <= (dataGridView.Rows.Count - 2))

    dataGridView.Rows(count).HeaderCell.Value = String.Format((count + 1).ToString(), "0")

    count += 1

    End While

    End If

End Sub

Or Go through this link-
how-to-add-an-autonumber-column-in-a-datagridview/[^]