TreeView子节点,点击出错!

[lishishui1216]

protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
{
TreeNode tnSelectedNode = TreeView1.SelectedNode;
iSelectIndex = Convert.ToInt32(tnSelectedNode.Value);
addSubNode();
}
protected void addSubNode()
{
string strCommandText = "select * from tbl_Root" ;
SqlDataAdapter objAdapterFolder = new SqlDataAdapter(strCommandText, objConn);
DataSet dsFavoriteFolder = new DataSet();
objAdapterFolder.Fill(dsFavoriteFolder);
for (int i = 0; i < dsFavoriteFolder.Tables[0].Rows.Count; i++)
{
//为TreeView添加节点
TreeNode tnChild = new TreeNode();
tnChild.Text = dr["RootName"].ToString();
tnChild.Value = dr["RootID"].ToString();
TreeView1.SelectedNode.ChildNodes.Add(tnChild);
}
}

我想在用户点击某节点后,给该节点添加满足条件的子节点.但添加子节点后,在点击该子节点,出错!

[myvicy]

出什么错了?
你给该节点加一个变量，用来保存是否已经添加过，如果添加过了就不要再添加了，没有则添加。

[lishishui1216]

protected void TreeView1_SelectedNodeChanged(object sender, EventArgs e)
{
TreeNode tnSelectedNode = TreeView1.SelectedNode;
iSelectIndex = Convert.ToInt32(tnSelectedNode.Value);
addSubNode();
}
TreeNode tnSelectedNode = TreeView1.SelectedNode;
tnSelectedNode 为null

[wpjwll]

up