Nanook.QueenBee.EditorForm.populateQbList C# (CSharp) Method

        private void populateQbList(QbItemBase selectItem)
        {
            ListViewItem topItem = null;
            try
            {
                bool isRefresh = (selectItem != null);

                lstQbItems.BeginUpdate();

                //try to preserve the top item
                ListViewItem top = lstQbItems.TopItem; //can return null
                int topIdx = 0;

                //if is refresh, try and select the same item
                if (isRefresh && top != null)
                {
                    for (int i = 0; i < lstQbItems.Items.Count; i++)
                    {
                        if (lstQbItems.Items[i] == top)
                        {
                            topIdx = i;
                            break;
                        }
                    }
                }

                //clear items without as much flicker as Items.Clear
                for (int i = lstQbItems.Items.Count - 1; i >= 0; i--)
                    lstQbItems.Items.RemoveAt(i);

                foreach (QbItemBase itm in _qbFile.Items)
                {
                    addItemToGui(itm, 0);
                    addSubItemsToGui(itm, 0 + 1);

                }

                ListViewItem foundItem = null;
                if (selectItem != null)
                {
                    foreach (ListViewItem li in lstQbItems.Items)
                    {
                        if (li.Tag == selectItem)
                        {
                            foundItem = li;
                            break;
                        }
                    }
                }

                if (foundItem == null && lstQbItems.Items.Count != 0)
                    foundItem = lstQbItems.Items[0];

                if (isRefresh && top != null && lstQbItems.Items.Count != 0 && topIdx >= 0 && topIdx < lstQbItems.Items.Count)
                {
                    topItem = lstQbItems.Items[topIdx];
                    lstQbItems.TopItem = topItem;
                    lstQbItems.TopItem = topItem; //crazy, but stops the wrong item being set.
                }

                if (foundItem != null)
                {
                    foundItem.Selected = true;
                    foundItem.Focused = true;
                    foundItem.EnsureVisible();
                }

                if (lstQbItems.SelectedIndices.Count == 0 && lstQbItems.Items.Count != 0)
                {
                    lstQbItems.Items[0].Selected = true;
                    lstQbItems.Items[0].Focused = true;
                }

                if (lstQbItems.SelectedIndices.Count == 0)
                {
                    gboEdit.Controls.Clear();
                }

                tlblQbFileInfo.Text = string.Format("QB file: {0} items, {1} bytes", lstQbItems.Items.Count.ToString(), _qbFile.Length.ToString());
            }
            catch (Exception ex)
            {
                showException("QB List Population Error", ex);
                clearInterfaceQb();
                return;
            }
            finally
            {
                lstQbItems.EndUpdate();
            }
        }