Filter TreeView Nodes in PowerShell - winforms

Question

I have a ton of Nodes in my TreeView, and have a textbox that filters through them to highlight the matched search. However, its a bit messy as it shows all the other nodes, and after I change my search, it leaves all nodes expanded.
I am trying to make something like this, https://www.codeproject.com/Tips/1000621/Filtering-and-Hiding-Tree-Nodes-WinForms
But I am using Windows forms / Powershell ISE and seem to struggle with implementing it into my own code.
For closing nodes I tried using things along the line of (Textbox.textlength -eq 0) to trigger a close all nodes function, but that was not working.
Here is what I want it too look like. Left is what I want, Right is what mine looks like.
Here is an example of the search function I am using.
Add-Type -AssemblyName System.Windows.Forms
function GetNodes([System.Windows.Forms.TreeNodeCollection] $nodes)
{
foreach ($n in $nodes) {
$n
GetNodes($n.Nodes)
}
}
$form = New-Object System.Windows.Forms.Form
$form.Text ="Test"
$form.Controls.AddRange(#(
($txt = [System.Windows.Forms.TextBox] #{
Location = [System.Drawing.Point]::new(8, 8);
Width = 100;
}),
($btn = [System.Windows.Forms.Button] #{
Location = [System.Drawing.Point]::new(120, 8);
Width = 50;
Text = "Search";
}),
($tree = [System.Windows.Forms.TreeView] #{
Location = [System.Drawing.Point]::new(8, 40);
Width = 170;
HideSelection = $false
})
))
$form.AcceptButton= $btn
$tree.Nodes.Add("A1", "A1")
$tree.Nodes.Add("A2", "A2")
$tree.Nodes[0].Nodes.Add("A11", "A11")
$tree.Nodes[0].Nodes.Add("A12", "A12")
$tree.Nodes[1].Nodes.Add("A21", "A21")
$tree.Nodes[1].Nodes.Add("A22", "A22")
$btn.Add_Click({param($sender,$e)
$nodes = GetNodes($tree.Nodes)
foreach ($node in $nodes) {
if($node.Text -like $txt.Text){
$tree.SelectedNode = $node
$node.EnsureVisible()
break
}
}
})
$form.ShowDialog() | Out-Null
$form.Dispose()

Answer 1

Assuming you are searching on a data source like a folder structure, this is what I'll do:
Create a function to get list of all directories recursively into a list
Create a function to filter the list of directories and return a list of directories which contain a specific text in their names.
Create a function to populate treeview
create a function to highlight treenode if it contains a specific text
Then in the text-changed event of the textbox, I'll filter and highlight tree:
Here is the code:
Add-Type -AssemblyName System.Windows.Forms
function GetPaths($root)
{
Get-ChildItem $root -Recurse -Directory | % {
$_.FullName.Replace($root, "").Trim("\")}
}
function FilterPaths($paths, $like)
{
$paths | ? {$_ -like "*$like*"} | % {
$i = $_.LastIndexOf("$like", [System.Globalization.CompareOptions]::IgnoreCase)
if($i -gt -1) {
$j = $_.IndexOf("\", $i, [System.Globalization.CompareOptions]::IgnoreCase)
if($j -gt -1) {
$_.SubString(0,$j)
} else {
$_
}
}
}
}
function GetNodes($nodes)
{
foreach ($n in $nodes) {
$n
GetNodes($n.Nodes)
}
}
function HighlightNodes($nodes, $like)
{
if(!$like){ return }
$nodes | ? {$_ -like "*$like*"} | % {
$_.BackColor = "Yellow"
}
}
function PopulateTree($treeView, $paths)
{
$treeView.Nodes.Clear()
foreach ($path in $paths)
{
$lastNode = $null
$subPathAgg = ""
foreach ($subPath in ($path -split '\\'))
{
$subPathAgg += ($subPath + '\')
$nodes = $treeView.Nodes.Find($subPathAgg, $true)
if ($nodes.Length -eq 0) {
if ($lastNode -eq $null) {
$lastNode = $treeView.Nodes.Add($subPathAgg, $subPath)
} else {
$lastNode = $lastNode.Nodes.Add($subPathAgg, $subPath)
}
} else {
$lastNode = $nodes[0]
}
}
}
}
$form = New-Object System.Windows.Forms.Form
$form.Text ="Test"
$form.Controls.AddRange(#(
($txt = [System.Windows.Forms.TextBox] #{
Location = [System.Drawing.Point]::new(8, 8);
Width = $form.ClientSize.Width - 16;
Anchor = [System.Windows.Forms.AnchorStyles]13
}),
($tree = [System.Windows.Forms.TreeView] #{
Location = [System.Drawing.Point]::new(8, 40);
Width = $form.ClientSize.Width - 16;
Anchor = [System.Windows.Forms.AnchorStyles]15
Height = 200;
HideSelection = $false
})
))
$form.AcceptButton= $btn
$root = "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\ItemTemplates\CSharp"
$paths = GetPaths $root
PopulateTree $tree $paths
$tree.ExpandAll()
$txt.Add_TextChanged({param($sender,$e)
$tree.BeginUpdate()
$like = $txt.Text
$filtered = FilterPaths $paths $like
PopulateTree $tree $filtered
HighlightNodes (GetNodes $tree.Nodes) $like
$tree.ExpandAll()
$tree.TopNode = $tree.Nodes[0]
$tree.EndUpdate()
})
$form.ShowDialog() | Out-Null
$form.Dispose()