问删除最旧项时防止ListView垂直滚动

EN

// loop through every item in the list from the top, until we find one that is
// within the listview's visible area
private int GetListViewTopVisibleItem()
{
    foreach (ListViewItem item In ListView1.Items)
    {
        if (ListView1.ClientRectangle.IntersectsWith(item.GetBounds(ItemBoundsPortion.Entire)))
        {
            // +2 as the above intersection doesn't take into account the height
            // of the listview's header (in Detail mode, which my listview is)
            return (item.Index + 2);
        }
    }
    // failsafe: return a valid index (which won't be used)
    return 0;
}

private void RemoveOldestItem()
{
    // pause redrawing of the listview while we fiddle...
    ListView1.SuspendLayout();

    // if we are not auto-scrolling to the most recent item, and there are
    // still items in the list:
    int TopItemIndex = 0;
    if (!AllowAutoScroll && (ListView1.SelectedItems.Count > 0))
        TopItemIndex = GetListViewTopVisibleItem();

    // remove the first item in the list
    ListView1.Items.RemoveAt(0);

    // if we are not auto-scrolling, and the previous top visible item was not
    // the one we just removed, make that previously top-visible item visible
    // again.  (We decrement TopItemIndex as we just removed the first item from
    // the list, which means all indexes have shifted down by 1)
    if (!AllowAutoScroll && (--TopItemIndex > 0))
        ListView1.Items(TopItemIndex).EnsureVisible();

    // allow redraw of the listview now
    ListView1.ResumeLayout()
}