//event handler for the Item Expanded event
void ItemExpanded(object sender, RoutedEventArgs e)
{
TreeViewItem itemExpanded = (TreeViewItem)e.OriginalSource;
//get the object being expanded
DirectoryDisplayItem displayItem = (DirectoryDisplayItem)itemExpanded.Header;
//check if the children of this item are dummy items
if (displayItem.ContainsDummyItems)
{
//if the children are dummy children replace them with the actual data
displayItem.ChildItems.Clear();
var modelData = FileSystemDataService.GetChildDirectories(displayItem.Path);
if (modelData != null)
{
var children = from x in modelData
select new DirectoryDisplayItem {
Name = x.Name, Path = x.FullName
};
//add all the data to the list
foreach (var child in children)
{
displayItem.ChildItems.Add(child);
}
displayItem.ContainsDummyItems = false;
}
}
}
//load all the files for the directory
private void LoadFiles(DirectoryDisplayItem dir)
{
if (dir != null)
{
DataSource = FileSystemDataService.GetChildFiles(dir.Path);
}
}
/// <summary>
/// Checks if the specified item is a dummy item
/// </summary>
/// <param name="item">The item to check</param>
/// <returns>Returns true if the item is a dummy item</returns>
public static bool IsDummyItem(DirectoryDisplayItem item)
{
return(item.Name == DummyItem);
}