Hallo zusammen, habe es mittlerweile mit Umwegen und Zwischenvariablen geschafft mein Problem zu erreichen

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Security;
using System.Security.Permissions;
using System.Security.Policy;
using System.Runtime.InteropServices;
using System.Collections;
using System.Data.SqlClient;
using System.Xml;

namespace WindowsFormsApplication1
{
    public partial class Form4 : Form
    {
        Hashtable treenodes = new Hashtable();
        ArrayList openNodes = new ArrayList();
        public Form4(string Src)
        {
            InitializeComponent();
            drives_Src(Src);  
            checkNodes(Src);
        }

        private void drives_Src(string source)
        {
            TreeNode node = new TreeNode();
             
            foreach (string drive in Directory.GetLogicalDrives())
            {
                try
                {
                    string NodeSrc = "";
                    Boolean fehler = true;
                    string NodeSource = "";
                    string[] sources = source.Split('|');
                    foreach (string strSource in sources)
                    {
                        string[] strNode = strSource.Split('\\');
                        string NodeSrctemp = strNode[0] + "\\";
                        if (drive == NodeSrctemp)
                        {
                            if (NodeSrctemp == NodeSrc)
                            {
                                NodeSource = NodeSource + "|" + strSource;
                                fehler = false;
                            }
                            else
                            {
                                NodeSrc = NodeSrctemp;
                                NodeSource = strSource;
                                fehler = false;
                            }
                        }
                    }
                    if (fehler == false)
                    {
                        eNode_Src(NodeSource,drive);
                    }
                    else
                    {
                        DriveType drive_type = GetDriveType(drive);
                        string[] strdrive = drive.Split('\\');
                        node = treeView1.Nodes.Add(drive);

                        switch (drive_type.ToString())
                        {
                            case "DRIVE_FIXED":
                                node.ImageKey = "drive";
                                node.SelectedImageKey = "drive";
                                break;
                            case "DRIVE_REMOTE":
                                node.ImageKey = "network";
                                node.SelectedImageKey = "network";
                                break;
                            case "DRIVE_CDROM":
                                node.ImageKey = "cdrom";
                                node.SelectedImageKey = "cdrom";
                                break;
                            default:
                                node.ImageKey = "drive";
                                node.SelectedImageKey = "drive";
                                break;
                        }

                        //Dummynodes einfügen
                        TreeNode dummy = new TreeNode();
                        dummy = node.Nodes.Add("");
                        dummy.ImageKey = "folder";
                    }
                }
                catch { }
            }
        } //Ende drives_Src()

        public enum DriveType
        {
            DRIVE_UNKNOWN = 0,
            DRIVE_NO_ROOT_DIR = 1,
            DRIVE_REMOVABLE = 2,
            DRIVE_FIXED = 3,
            DRIVE_REMOTE = 4,
            DRIVE_CDROM = 5,
            DRIVE_RAMDISK = 6
        } //Ende DriveType

        // Um heraus zu finden um was für ne laufwerksart es sich handelt...
        [DllImport("KERNEL32", EntryPoint = "GetDriveType")]
        public static extern DriveType GetDriveType(string sDrive);

        int i = 0;

        // TreeView Quelle
        private void eNode_Src(string SrcNodes, string drive)
        {
            TreeNode parentNode = null;
            
            string[] Sources = SrcNodes.Split('|');
            foreach (string Source in Sources)
            {
                TreeNode tmp = null;
                string SrcPart = "";
                string[] splittetSrc = Source.Split('\\');
                foreach (string SrcParted in splittetSrc)
                {

                    if (SrcPart == "")
                    {
                        SrcPart = SrcParted + "\\";
                        Boolean vorhanden = false;

                        foreach (DictionaryEntry node in treenodes)
                        {
                            if (node.Value.ToString() == SrcPart)
                            {
                                vorhanden = true;
                                parentNode = (TreeNode)node.Key;
                            }
                        }

                        if (vorhanden != true)
                        {
                            parentNode = treeView1.Nodes.Add(drive);
                            parentNode.Expand();
                            treenodes.Add(parentNode, drive); 
                        }                    
                    }
                    else
                    {
                        SrcPart += SrcParted + "\\";
                        parentNode = tmp;
                    }
                    foreach (string dir in Directory.GetDirectories(SrcPart))
                    {
                        try
                        {
                            Boolean vorhanden = false;
                            TreeNode dir_t = new TreeNode();
                            TreeNode test = new TreeNode();
                            string[] ordnername = dir.Split('\\');
                            i = ordnername.Length - 1;

                            foreach (DictionaryEntry node in treenodes)
                            {
                                if (node.Value.ToString() == dir)
                                {
                                    vorhanden = true;
                                    if (Source.Contains(dir) && dir != Source)
                                    {
                                        parentNode.Nodes.Remove((TreeNode)node.Key);
                                        dir_t = parentNode.Nodes.Add(ordnername[i].ToString());
                                        this.treeView1.Sort();
                                        dir_t.Expand();
                                        dir_t.ImageKey = "folder";
                                        dir_t.SelectedImageKey = "folder";
                                        tmp = dir_t;
                                    }
                                }
                            }
                            if (vorhanden != true)
                            {
                                dir_t = parentNode.Nodes.Add(ordnername[i].ToString());
                                dir_t.Expand();
                                dir_t.ImageKey = "folder";
                                dir_t.SelectedImageKey = "folder";
                                if (Source.Contains(dir))
                                {
                                    tmp = dir_t;
                                }
                                treenodes.Add(dir_t, dir); 
                            }
                        }
                        catch (Exception ex)
                        {
                            MessageBox.Show("Catch: " + ex.Message + " dir: " + dir);
                        }
                    }
                }
            }
        }//Ende treeView1 (Quelle)

        private void checkNodes(String SrcNodes)
        {
            string[] tmpSources = SrcNodes.Split('|');
            foreach (string Source in tmpSources)
            {
                //String Source vorbereiten
                string strTemp = "";
                string[] strSource = Source.Split('\\');

                foreach (string tmpStr in strSource)
                {
                    if (strTemp == "")
                    {
                        strTemp = tmpStr + "\\";
                    }
                    else
                    {
                        strTemp += "\\" + tmpStr;
                    }
                }

                // Hier werden die Nodes gecheckt
                CallRecursive(treeView1, strTemp);
            }
        }

        private void PrintRecursive(TreeNode treeNode, String Source)
        {

            if (treeNode.Text != "")
            {
                if (treeNode.FullPath == Source)
                {
                    treeNode.Checked = true;
                }
            }

            foreach (TreeNode tn in treeNode.Nodes)
            {
                PrintRecursive(tn, Source);
            }
        }

        // Call the procedure using the TreeView.
        private void CallRecursive(TreeView treeView, string Source)
        {
            TreeNodeCollection nodes = treeView.Nodes;
            foreach (TreeNode n in nodes)
            {
                PrintRecursive(n, Source);
            }
        }
    }
}