[RESOLVED] DataGridView: Upper left blank cell occasionally missing when using row headers

[pel11]

Since row headers are not persistent in the DataGridView (DGV), I use an AddHandler to call the method below, which adds row header numbers whenever the DGV is shown or modified. You will note that the Addhandler is cancelled at the end, so that this method won't activate when a new cell/record/column is modified or the DGV is sorted by the user. It works seamlessly without any exceptions, however, on occasion the column headers are not arranged correctly (see image). Is there anything in the method's code that would be suspect for this behavior. Maybe I need to add some code?

 Sub DGV1datachanged(ByVal sender As Object, ByVal e As EventArgs)
        If TypeOf sender Is DataGridView Then
            Dim dgv As DataGridView = CType(sender, DataGridView) 
            AddHandler dgv.Sorted, AddressOf DGV1sorted
            If dgv.Rows.Count - 1 <> NumInputObjects Then Exit Sub
            If dgv.Columns.Count = 0 Then Exit Sub
            Dim cnt As Integer = 0
            For Each row As DataGridViewRow In dgv.Rows
                If cnt > dgv.Rows.Count - 2 Then Exit For
                dgv.Rows(cnt).HeaderCell.Value = (cnt + 1).ToString
                cnt += 1
            Next
            Dim dgvColumnHeaderStyle As New DataGridViewCellStyle()
            dgvColumnHeaderStyle.Alignment = DataGridViewContentAlignment.MiddleCenter
            dgv.ColumnHeadersDefaultCellStyle = dgvColumnHeaderStyle
            dgv.EnableHeadersVisualStyles = True
            dgv.ColumnHeadersDefaultCellStyle.ForeColor = Color.Black
            dgv.RowHeadersDefaultCellStyle.ForeColor = Color.Black
            dgv.RowHeadersVisible = True
            dgv.RowHeadersWidth = (Len(cnt.ToString)) * 15
            dgv.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.DisplayedCells
            dgv.RowsDefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleCenter
            dgv.Refresh()
            RemoveHandler dgv.DataBindingComplete, AddressOf DGV1datachanged
        End If
End Sub

[pel11]

It appears that after I moved the following three lines before the loop that adds row numbers to the row header values, it will work. I checked if dgv.TopLeftHeaderCell.Visible was True, and it was. So its width was just not getting set to the width of the maximum number of rows. Now, I set the row header width before adding row numbers, and it seems to be resolved.

  dgv.RowHeadersWidth = (Len(dgv.Rows.Count.ToString)) * 20
  dgv.RowHeadersDefaultCellStyle.ForeColor = Color.Black
  dgv.RowHeadersVisible = True

[jmcilhinney]

If your problem has been resolved, please use the Thread Tools menu to mark the thread Resolved, so everyone knows that you don't need any further help without opening the thread and reading the whole thing. I have done so for you this time.

[pel11]

Thanks!