Problems with populating a treeview

[BustedPixel]

Hello everyone,
This is my first post and I was wondering if anyone can help me. I am trying to populate user selected files (file path) into a treeview, but whenever I select multiple files from the same sub folder, it displays the root path and sub folder for each file.

private void BrowseButton_Click(object sender, EventArgs e)
        {
            // open file dialog method - set initial directory, filter and title
            OpenFileDialog.InitialDirectory = @"E:\AIR";
            OpenFileDialog.Filter = "Data Sources (*.txt, *.html)|*.txt*;*.html|All Files|*.*";
            OpenFileDialog.Title = "Select a file";

            // calls open file dialog method
            if (OpenFileDialog.ShowDialog() == DialogResult.OK)
            {
                // places selected files into an array
                fileArray = OpenFileDialog.FileNames;

                foreach (string file in fileArray)
                {
                    string folderDirectory = System.IO.Path.GetDirectoryName(file);
                    string[] folders = folderDirectory.Split('\\');

                    RichTextBox1.Text = folderDirectory;

                    TreeNode rootNode = new TreeNode();

                    // checks if rootNode contains key
                    
                    if (treeView1.Nodes.ContainsKey(folders[0]))
                    {
                        rootNode = treeView1.Nodes[folders[0]];
                    }
                    else
                    {
                        rootNode = treeView1.Nodes.Add(folders[0]);
                    }

                    // for loop which calls AddNode function
                    for (int i = 1; i < folders.Length; i++)
                    {
                        rootNode = AddNode(rootNode, folders[i]);
                    }

                    // gets and adds file name to root node
                    string fileNode = System.IO.Path.GetFileName(file);
                    rootNode.Nodes.Add(fileNode);
                }
            }
        }

        
        private TreeNode AddNode(TreeNode node, string key)
        {            
            if (node.Nodes.ContainsKey(key))
            {
                return node.Nodes[key];
            }
            else
            {
                return node.Nodes.Add(key, key);
            }
        }

The output is like this:
E:
+--AIR
+--Test Files
+-- .txt file 1
E:
+--AIR
+--Test Files
+-- .txt file 2

If someone can help, I would greatly appreciate this.

[ddanbe]

It seems that in your foreach statement you are always making a new rootnode.

[Ramy Mahrous]

I'm not going to give quick solution because I couldn't review your code, so I suggest to use your true eyes F5; debug the application and but break points it'd lead you to the logic error.

[BustedPixel]

It seems that in your foreach statement you are always making a new rootnode.

Thanks for the response. I moved the rootnode out of the foreach statement and still getting the same output. When I try to debug, I notice that in the AddNode method, it always skips the if statement and goes directly to the else statement and returns node.Nodes.Add(key, key). Correct me if I'm wrong, but I thought that ContainsKey checks to see if it has been used already