public void OnCollectionItemAdded(object sender, EventItemArgs e)
{
int height = e.Item.MeasureItem();
int lastTotalHeight = itemTotalHeight;
itemTotalHeight += height;
itemCacheHeight.Add(height);
// Update last visible item index
if (scroll.Value + this.Height > lastTotalHeight)
{
itemLastVisibleIndex = GetLastVisibleItemIndex();
}
Update();
}
public void OnCollectionItemRemoved(object sender, EventItemArgs e)
{
int height = e.Item.MeasureItem();
itemTotalHeight -= height;
itemCacheHeight.RemoveAt(e.Item.Index);
if (e.Item.Selected)
{
itemSelectedList.Remove(e.Item);
if (_selectedIndex == e.Item.Index)
{
if (itemSelectedList.Count > 0)
{
_selectedIndex = itemSelectedList[0].Index;
}
else
{
_selectedIndex = -1;
}
}
}
// Update first visible item index and last visible item index accordingly
if (e.Item.Index <= itemFirstVisibleIndex)
{
UpdateItemVisibilityByChange(-height);
itemLastVisibleIndex = GetLastVisibleItemIndex();
}
else if (e.Item.Index <= itemLastVisibleIndex)
{
itemLastVisibleIndex = GetLastVisibleItemIndex();
}
Update();
}