TreeView查获节点并选中节点

        private void SearchNodes(string SearchText, TreeNode StartNode)
        {
            TreeNode node = null;
            while (StartNode != null)
            {
                if (StartNode.Text.ToLower().Contains(SearchText.ToLower()))
                {
                    CurrentNodeMatches.Add(StartNode);
                }

                if (StartNode.Nodes.Count != 0)
                {
                    SearchNodes(SearchText, StartNode.Nodes[0]);//Recursive Search 
                }
                StartNode = StartNode.NextNode;
            }
        }

 private List<TreeNode> CurrentNodeMatches = new List<TreeNode>();
        private int LastNodeIndex = 0;
        private string LastSearchText;

        
        private void SearchNodeText_Click(object sender, EventArgs e)
        {
            treeView1.Focus();
            string searchText = this.textBox7.Text;/////////////////
            if (String.IsNullOrEmpty(searchText))
            {
                return;
            }

            if (LastSearchText != searchText)
            {
                //It‘s a new Search
                CurrentNodeMatches.Clear();
                LastSearchText = searchText;
                LastNodeIndex = 0;
                SearchNodes(searchText, treeView1.Nodes[0]);

            }

            if (CurrentNodeMatches.Count == 0)
             MessageBox.Show("无查找记录!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);

            if (LastNodeIndex >= 0 && CurrentNodeMatches.Count > 0 && LastNodeIndex < CurrentNodeMatches.Count)
            {
                TreeNode selectedNode = CurrentNodeMatches[LastNodeIndex];
                LastNodeIndex++;
                this.treeView1.SelectedNode = selectedNode;
                this.treeView1.SelectedNode.Expand();
                this.treeView1.Select();
            }
            else
                LastNodeIndex = 0;  
        }