c # Treeview filter and binding

        /// <summary>
        /// fuzzy query
        /// </summary>
        /// <param name="str"></param>
        /// <param name="list"></param>
        /// <returns></returns>
        private IList<CV_QM_DEFECT_LABEL_GROUP> onFindKeyWord(string str, IList<CV_QM_DEFECT_LABEL_GROUP> list)
        {

            List<CV_QM_DEFECT_LABEL_GROUP> m_list = new List<CV_QM_DEFECT_LABEL_GROUP>();
            foreach (CV_QM_DEFECT_LABEL_GROUP data in list)
            {
                if (data.GroupName.IndexOf(str) != -1)
                {
                    m_list.Add(data);
                }
            }
            return m_list;

        }
        /// <summary>
        /// find all the relevant root
        /// </summary>
        private List<CV_QM_DEFECT_LABEL_GROUP> findparent()
        {
            IList<CV_QM_DEFECT_LABEL_GROUP> entities = this.icv_QM_DEFECT_LABEL_GROUPBO_0.GetEntities();
            IList<CV_QM_DEFECT_LABEL_GROUP> filterdata = onFindKeyWord(txtquery.Text.Trim(), entities);
            List <CV_QM_DEFECT_LABEL_GROUP> entities1 = new List <CV_QM_DEFECT_LABEL_GROUP> (); // list into easy to use
            List <CV_QM_DEFECT_LABEL_GROUP> entities2 = new List <CV_QM_DEFECT_LABEL_GROUP> (); // for storing all nodes

            foreach (var item in (IList<CV_QM_DEFECT_LABEL_GROUP>)entities)
            {
                entities1.Add(item);
            }
            foreach (CV_QM_DEFECT_LABEL_GROUP data in filterdata)
            {
                CV_QM_DEFECT_LABEL_GROUP temp1 = data;
                while (true)
                {
                    if (temp1.ParentGroupID.HasValue)
                    {
                        if (entities2.Find(s => s.GroupID.Equals(temp1.GroupID)) == null)
                        { entities2.Add(temp1); }
                        CV_QM_DEFECT_LABEL_GROUP temp = entities1.Find(s => s.GroupID.Equals(temp1.ParentGroupID));
                        temp1 = temp;
                    }
                    else
                    {
                        if (entities2.Find(s => s.GroupID.Equals(temp1.GroupID)) == null)
                        { entities2.Add(temp1); }
                        break;
                    }
                }
            }
            return entities2.OrderBy(item => item.GroupLevel).ToList();
        }
        /// <summary>
        /// Data Binding
        /// </summary>
        private void bind()
        {
            IList<CV_QM_DEFECT_LABEL_GROUP> entities = findparent();
            this.TreeView1.Nodes.Clear();
            foreach (CV_QM_DEFECT_LABEL_GROUP cv_qm_defect_label_group in entities)
            {
                if (cv_qm_defect_label_group.ParentGroupID.HasValue)
                {
                    TreeNode[] nodeArray = this.TreeView1.Nodes.Find(cv_qm_defect_label_group.ParentGroupID.Value.ToString(), true);
                    if ((nodeArray != null) && (nodeArray.Length > 0))
                    {
                        nodeArray[0].Nodes.Add(cv_qm_defect_label_group.GroupID.Value.ToString(), cv_qm_defect_label_group.GroupName, "Group.png", "Group.png");
                        nodeArray[0].Nodes[cv_qm_defect_label_group.GroupID.Value.ToString()].Tag = cv_qm_defect_label_group;
                    }
                    else
                    {
                        this.TreeView1.Nodes.Add(cv_qm_defect_label_group.GroupID.Value.ToString(), cv_qm_defect_label_group.GroupName, "Group.png", "Group.png");
                        this.TreeView1.Nodes[cv_qm_defect_label_group.GroupID.Value.ToString()].Tag = cv_qm_defect_label_group;
                    }
                }
                else
                {
                    this.TreeView1.Nodes.Add(cv_qm_defect_label_group.GroupID.Value.ToString(), cv_qm_defect_label_group.GroupName, "Group.png", "Group.png");
                    this.TreeView1.Nodes[cv_qm_defect_label_group.GroupID.Value.ToString()].Tag = cv_qm_defect_label_group;
                }
            }
            this.TreeView1.ExpandAll();
        }

    }
}