tree 在服务器端折叠与展开

protected void Log_Person_View_TreeNodeExpanded(object sender, TreeNodeEventArgs e)
    {
      
    
        TreeNodeCollection ts = null;
        if (e.Node.Parent == null)
        {
            ts = ((TreeView)sender).Nodes;
        }
        else
            ts = e.Node.Parent.ChildNodes;

        foreach (TreeNode node in ts)
        {
            if (node != e.Node)
            {
                node.Collapse();
            }
        }

    }