internal NativeListViewItem GetItem(
object item)
{
NativeListViewItem customItem;
if (!this._customItemMap.TryGetValue(item, out customItem))
{
customItem = new NativeListViewItem(item);
this._customItemMap.Add(item, customItem);
}
return(customItem);
}
public object this[int index]
{
get
{
object item = this._source[index];
NativeListViewItem customItem = GetItem(item);
return(customItem);
}
set
{
throw new NotImplementedException();
}
}
private IList <NativeListViewItem> MapCustomItems(
IList changeList)
{
if (changeList == null)
{
return(null);
}
List <NativeListViewItem> list = new List <NativeListViewItem>(changeList.Count);
foreach (object item in changeList)
{
NativeListViewItem customItem = GetItem(item);
list.Add(customItem);
}
return(list);
}
private void EnsureItemIsVisible(
object item)
{
// Get the native list item container
NativeListViewItem customItem = this._customSource.GetItem(item);
var selectorItem = this.ContainerFromItem(customItem) as FrameworkElement;
if (null == selectorItem)
{
// Item is not realized in the list view (it is virtualized)
return;
}
// Find the offset of the item from the top of the view
var selectorItemTop = selectorItem.TransformToVisual(this).TransformPoint(new global::Windows.Foundation.Point(0, 0));
// Get the height of the item
var itemHeight = selectorItem.ActualHeight;
// Determine whether or not scrolling is necessary
double scrollBy = 0;
if (selectorItemTop.Y < 0)
{
scrollBy = selectorItemTop.Y;
}
else if (selectorItemTop.Y + itemHeight > this.ActualHeight - this.FooterHeight)
{
scrollBy = selectorItemTop.Y + itemHeight - this.ActualHeight + this.FooterHeight;
}
if (scrollBy != 0)
{
var scrollViewer = GetScrollViewer(this);
scrollViewer.ChangeView(null, scrollViewer.VerticalOffset + scrollBy, zoomFactor: null, disableAnimation: false);
}
}
