/// <summary>
/// Gets the items that are currently in the viewport
/// of a LongListSelector and adds them
/// into a list of weak references.
/// </summary>
/// <param name="list">
/// The LongListSelector instance to search on.
/// </param>
/// <param name="items">
/// The list of weak references where the items in
/// the viewport will be added.
/// </param>
public static void GetItemsInViewPort(LongListSelector list, IList<WeakReference> items)
{
DependencyObject child = list;
if (VisualTreeHelper.GetChildrenCount(list) == 0)
{
// no child yet
return;
}
list.UpdateLayout();
do
{
child = VisualTreeHelper.GetChild(child, 0);
} while (VisualTreeHelper.GetChildrenCount(child) > 0 && !(child is Canvas));
if (child is Canvas &&
VisualTreeHelper.GetChildrenCount(child) > 0 &&
VisualTreeHelper.GetChild(child, 0) is Canvas)
{
Canvas headersPanel = (Canvas)child;
Canvas itemsPanel = (Canvas)VisualTreeHelper.GetChild(child, 0);
var itemsInList = new List<KeyValuePair<double, FrameworkElement>>();
AddVisibileContainers(list, itemsPanel, itemsInList, /* selectContent = */ false);
AddVisibileContainers(list, headersPanel, itemsInList, /* selectContent = */ true);
foreach (var pair in itemsInList.OrderBy(selector => selector.Key))
{
items.Add(new WeakReference(pair.Value));
}
}
}
/// <summary>
/// Gets the items that are currently in the viewport
/// of a LongListSelector and adds them
/// into a list of weak references.
/// </summary>
/// <param name="list">
/// The LongListSelector instance to search on.
/// </param>
/// <param name="items">
/// The list of weak references where the items in
/// the viewport will be added.
/// </param>
public static void GetItemsInViewPort(LongListSelector list, IList <WeakReference> items)
{
DependencyObject child = list;
if (VisualTreeHelper.GetChildrenCount(list) == 0)
{
// no child yet
return;
}
list.UpdateLayout();
do
{
child = VisualTreeHelper.GetChild(child, 0);
} while (VisualTreeHelper.GetChildrenCount(child) > 0 && !(child is Canvas));
if (child is Canvas &&
VisualTreeHelper.GetChildrenCount(child) > 0 &&
VisualTreeHelper.GetChild(child, 0) is Canvas)
{
Canvas headersPanel = (Canvas)child;
Canvas itemsPanel = (Canvas)VisualTreeHelper.GetChild(child, 0);
var itemsInList = new List <KeyValuePair <double, FrameworkElement> >();
AddVisibileContainers(list, itemsPanel, itemsInList, /* selectContent = */ false);
AddVisibileContainers(list, headersPanel, itemsInList, /* selectContent = */ true);
foreach (var pair in itemsInList.OrderBy(selector => selector.Key))
{
items.Add(new WeakReference(pair.Value));
}
}
}
/// <summary>
/// Gets the items that are currently in the viewport of a
/// <see cref="T:LongListSelector" /> and adds them into a list of weak references.
/// </summary>
/// <param name="list">
/// The LongListSelector instance to search on.
/// </param>
/// <param name="items">
/// The list of weak references where the items in
/// the viewport will be added.
/// </param>
public static void GetItemsInViewPort(this LongListSelector list, IList <WeakReference> items)
{
DependencyObject child = list;
int childCount;
childCount = VisualTreeHelper.GetChildrenCount(list);
if (childCount == 0)
{
// no child yet
return;
}
list.UpdateLayout();
Canvas headersPanel;
do
{
child = VisualTreeHelper.GetChild(child, 0);
childCount = VisualTreeHelper.GetChildrenCount(child);
headersPanel = child as Canvas;
} while ((headersPanel == null) && childCount > 0);
if (headersPanel != null &&
childCount > 0)
{
Canvas itemsPanel = VisualTreeHelper.GetChild(headersPanel, 0) as Canvas;
if (itemsPanel != null)
{
var itemsInList = new List <KeyValuePair <double, FrameworkElement> >();
AddVisibileContainers(list, itemsPanel, itemsInList, /* selectContent = */ false);
AddVisibileContainers(list, headersPanel, itemsInList, /* selectContent = */ true);
foreach (var pair in itemsInList.OrderBy(selector => selector.Key))
{
items.Add(new WeakReference(pair.Value));
}
}
}
}