/// <summary>
/// Finds the provided object in an ItemsControl's children and selects it
/// </summary>
/// <param name="parentContainer">The parent container whose children will be searched for the selected item</param>
/// <param name="itemToSelect">The item to select</param>
/// <returns>True if the item is found and selected, false otherwise</returns>
private static bool ExpandAndSelectItem(ItemsControl parentContainer, object itemToSelect, bool isValue, string valuePath, Action <TreeViewItem> beforeSelection, Action <TreeViewItem> afterSelection)
{
//check all items at the current level
foreach (object item in parentContainer.Items)
{
TreeViewItem currentContainer = parentContainer.ItemContainerGenerator.ContainerFromItem(item) as TreeViewItem;
object equalItem = item;
if (isValue)
{
equalItem = BindingHelper.Eval <object>(item, valuePath);
}
//if the data item matches the item we want to select, set the corresponding
//TreeViewItem IsSelected to true
if (currentContainer != null)
{
if (equalItem.Equals(itemToSelect))
{
if (beforeSelection != null)
{
beforeSelection(currentContainer);
}
currentContainer.IsSelected = true;
currentContainer.BringIntoView();
currentContainer.Focus();
if (afterSelection != null)
{
afterSelection(currentContainer);
}
//the item was found
return(true);
}
else if (currentContainer.IsSelected)
{
currentContainer.IsSelected = false;
}
}
}
//if we get to this point, the selected item was not found at the current level, so we must check the children
foreach (object item in parentContainer.Items)
{
TreeViewItem currentContainer = parentContainer.ItemContainerGenerator.ContainerFromItem(item) as TreeViewItem;
//if children exist
if (currentContainer != null && currentContainer.Items.Count > 0)
{
//keep track of if the TreeViewItem was expanded or not
bool wasExpanded = currentContainer.IsExpanded;
//expand the current TreeViewItem so we can check its child TreeViewItems
currentContainer.IsExpanded = true;
//if the TreeViewItem child containers have not been generated, we must listen to
//the StatusChanged event until they are
if (currentContainer.ItemContainerGenerator.Status != GeneratorStatus.ContainersGenerated)
{
//store the event handler in a variable so we can remove it (in the handler itself)
EventHandler eh = null;
eh = new EventHandler(delegate
{
if (currentContainer.ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
if (ExpandAndSelectItem(currentContainer, itemToSelect, isValue, valuePath, beforeSelection, afterSelection) == false)
{
//The assumption is that code executing in this EventHandler is the result of the parent not
//being expanded since the containers were not generated.
//since the itemToSelect was not found in the children, collapse the parent since it was previously collapsed
currentContainer.IsExpanded = false;
}
//remove the StatusChanged event handler since we just handled it (we only needed it once)
currentContainer.ItemContainerGenerator.StatusChanged -= eh;
}
});
currentContainer.ItemContainerGenerator.StatusChanged += eh;
}
else //otherwise the containers have been generated, so look for item to select in the children
{
if (ExpandAndSelectItem(currentContainer, itemToSelect, isValue, valuePath, beforeSelection, afterSelection) == false)
{
//restore the current TreeViewItem's expanded state
currentContainer.IsExpanded = wasExpanded;
}
else //otherwise the node was found and selected, so return true
{
return(true);
}
}
}
}
//no item was found
return(false);
}