/// <summary>
/// Populate the contents of the node that is about to be expanded.
/// </summary>
/// <param name="e">the arguments giving the node to be expanded</param>
protected override void OnBeforeExpand(TreeViewCancelEventArgs e)
{
FileSystemTreeNode node = e.Node as FileSystemTreeNode;
if (node != null && node.IsExpandable)
{
BeginUpdate();
node.Nodes.Clear();
try
{
node.DoExpand();
node.SelectedImageIndex = node.ImageIndex = node.DisplayIcon;
}
catch (Exception ex)
{
node.Text = node.DisplayName + " : " + ex.Message;
node.IsExpandable = true;
e.Cancel = true;
}
finally
{
EndUpdate();
}
}
base.OnBeforeExpand(e);
}
/// <summary>
/// Called after a node is collapsed, used to remove the contents of the node
/// as node contents are generated when opened.
/// </summary>
/// <param name="e"></param>
protected override void OnAfterCollapse(TreeViewEventArgs e)
{
FileSystemTreeNode node = e.Node as FileSystemTreeNode;
if (node != null)
{
node.IsExpandable = true;
node.SelectedImageIndex = node.ImageIndex = node.DisplayIcon;
}
}
