File System TreeView

Question

Im working with file systems and I have a List<> of file objects that have the file path as a property. Basically I need to create a treeview in .NET but im struggling to

Answer 1

I would turn the string into a FileInfo.

Once you have the FileInfo object, you can use the Directory property to retrieve the DirectoryInfo for each path.

Once you have the DirectoryInfo for the path, it's easy to "walk up" the Parent reference in DirectoryInfo to turn each path into a list of directories + filename - ie:

{"C:","Windows","Temp","ErrorLog.txt"}

This should be fairly straightforward to insert into your treeview. Just look for each section of the path in turn, and if it doesn't exist, add it....

Answer 2

    private void Form1_Load(object sender, EventArgs e)
    {
        var paths = new List<string>
                        {
                            @"C:\WINDOWS\AppPatch\MUI\040C",
                            @"C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727",
                            @"C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\MUI",
                            @"C:\WINDOWS\addins",
                            @"C:\WINDOWS\AppPatch",
                            @"C:\WINDOWS\AppPatch\MUI",
                            @"C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\MUI\0409"
                        };
        treeView1.PathSeparator = @"\";
        PopulateTreeView(treeView1, paths, '\\');
    }

    private static void PopulateTreeView(TreeView treeView, IEnumerable<string> paths, char pathSeparator)
    {
        TreeNode lastNode = null;
        string subPathAgg;
        foreach (string path in paths)
        {
            subPathAgg = string.Empty;
            foreach (string subPath in path.Split(pathSeparator))
            {
                subPathAgg += subPath + pathSeparator;
                TreeNode[] nodes = treeView.Nodes.Find(subPathAgg, true);
                if (nodes.Length == 0)
                    if (lastNode == null)
                        lastNode = treeView.Nodes.Add(subPathAgg, subPath);
                    else
                        lastNode = lastNode.Nodes.Add(subPathAgg, subPath);
                else
                    lastNode = nodes[0];
            }
        }
    }

Answer 3

EHosca's piece worked for me perfectly, with one change - I had to set lastnode to nothing after the foreach path in paths area.

This is eHosca's code above, ported to VB.

Private Sub PopulateTreeView(tv As TreeView, paths As List(Of String), pathSeparator As Char)
    Dim lastnode As TreeNode = Nothing
    Dim subPathAgg As String
    For Each path In paths
        subPathAgg = String.Empty
        lastnode = Nothing
        For Each subPath In path.Split(pathSeparator)
            subPathAgg += subPath + pathSeparator
            Dim nodes() As TreeNode = tv.Nodes.Find(subPathAgg, True)
            If nodes.Length = 0 Then
                If IsNothing(lastnode) Then
                    lastnode = tv.Nodes.Add(subPathAgg, subPath)
                Else
                    lastnode = lastnode.Nodes.Add(subPathAgg, subPath)
                End If
            Else
                lastnode = nodes(0)
            End If
        Next
    Next
End Sub

Answer 4

give recursion a try.

private void AddFiles()
{
  // Iterate your list with FileInfos here
  foreach( var fileInfo in new Collection<FileInfo>() )
  {
    GetOrCreateTreeNode( fileInfo.Directory ).Nodes.Add( new TreeNode( fileInfo.Name ) );
  }
}

private TreeNode GetOrCreateTreeNode( DirectoryInfo directory )
{
  if( directory.Parent == null )
  {
    // Access your TreeView control here:
    var rootNode = <TreeView>.Nodes[directory.Name];
    if( rootNode == null )
    {
      rootNode = new TreeNode(directory.Name);
      // Access your TreeView control here:
      <TreeView>.Nodes.Add( rootNode );
    }
    return rootNode;
  }

  var parent = GetOrCreateTreeNode( directory.Parent );
  var node = parent.Nodes[directory.Name];
  if( node == null )
  {
    node = new DirectoryNode( directory );
    parent.Nodes.Add( node );
  }
  return node;
}

This code should give you only an idea - I have to admit that I did not test it before posting here.

Answer 5

If you wanted to stick with the strings something like this would work...

TreeNode root = new TreeNode();
TreeNode node = root;
treeView1.Nodes.Add(root);

 foreach (string filePath in myList) // myList is your list of paths
 {
    node = root;
    foreach (string pathBits in filePath.Split('/'))
    {
      node = AddNode(node, pathBits);
    }
 }


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