how to rowspan DataGridView in vb.net

Question

hi,

  how to rowspan DataGridView in vb.net.

I tried the following code,but  RowSpan error occured. 

 

  For i As Integer = DGGrid.Rows.Count - 1 To 1 Step -1

            Dim row As DataGridViewRow = DGGrid.Rows(i)

            Dim previousRow As DataGridViewRow = DGGrid.Rows(i - 1)

 

            For j As Integer = 0 To row.Cells.Count - 1           

                If previousRow.Cells(j).RowSpan = 0 Then

                    If row.Cells(j).RowSpan = 0 Then

                        previousRow.Cells(j).RowSpan += 2

                    Else

                        previousRow.Cells(j).RowSpan = row.Cells(j).RowSpan + 1

                    End If

                    row.Cells(j).Visible = False

                End If              

            Next

        Next

 

Please help.