学步园

二.前台:
只要一个TreeView控件,加上 TreeView1_SelectedNodeChanged 事件.

三.后台:

       protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
       {
            for (int i = 0; i < this.TreeView1.Nodes.Count; i++)
            {//跌迭根节点
                if (this.TreeView1 .SelectedValue==this.TreeView1 .Nodes [i].Value )
                {//如果选中的是根节点,就展开
                    this.TreeView1.SelectedNode.Expanded = true;
                }
                else
                {如果选中的不是根节点
                    for (int j = 0; j < this.TreeView1.SelectedNode.Parent.ChildNodes.Count; j++)
                    {//就让选中节点的所有同级节点收缩
                        this.TreeView1.SelectedNode.Parent.ChildNodes[j].CollapseAll();
                    }
                    //然后再展开选中的节点及其所有父节点
                    this.TreeView1.SelectedNode.Parent.Expanded = true;
                    this.TreeView1.SelectedNode.Expanded = true;
                }
           }
       }//end TreeView1_SelectedNodeChanged