如何获得TreeView的返回值，即子节点node.Name的值

DataTable dtGroupName = Cheeli.DBUtility.DbHelperSQL.GetDataTable
("select distinct GroupName from SysRes");           
 foreach (DataRow rows in dtGroupName.Rows){ 
               string GroupName = rows["GroupName"].ToString();                     TreeNode root = new TreeNode(GroupName);                
tvPermissions.Nodes.Add(root);                
SqlParameter[] parameters = 
{ new SqlParameter("@GroupNameText", root.Text) };                
string sql = "select * from SysRes where GroupName=@GroupNameText";                 DataTable dt = Cheeli.DBUtility.DbHelperSQL.GetDataTable(sql, parameters);                
foreach (DataRow row in dt.Rows){                    
string PromiseName = row["PromiseName"].ToString();                    
TreeNode node = new TreeNode(PromiseName);                    
node.Name = row["Id"].ToString();                    
root.Nodes.Add(node);                
}            
}

[解决办法]
return node.Name;