TreeView 节点 收缩其他未点击节点

 /// <summary>
    /// 树结点展开
    /// </summary>
    /// <param name="sender"></param>
    /// <param name="e"></param>
    #region TreeView1_TreeNodeExpanded
    protected void TreeView1_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();
            }
        }
    }
    #endregion