TreeView Find not working

treddie

Hi. For the life of me, I cannot get a TreeView Find to work. I have a list of drives, folders and subfolders in my TreeView. I have googled like crazy and either find repeated references to a very simple method, or convoluted methods that seem to apply to something else. Here is a very basic procedure that fails:

Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect

Me.TreeView1.SelectedNode = Me.TreeView1.Nodes.Find("Client Supplied Files", True)(0)

End Sub

I put the Find method in the _AfterSelect event only because I was using that event as a test area to do the find. In other words...If I clicked on any node in the tree, the event would cause the selected node to change to the one specified in the search. But alas, no go. :(( I have to be missing something really simple here. Thank you for any hints!

Lost User

treddie wrote:

I have a list of drives, folders and subfolders in my TreeView.

How did you load them? Something similar to this[^]? In that case not all nodes will be loaded when the control shows, only the nodes that are expanded.

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^]

treddie

Hm...I like that solution MUCH better. But in the interests of trying to understand why "my" version won't work (it was an online TreeView demo that I modified slightly), no, it was a fully recursive method. Please see code below:

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Go_cmd.Click
'Get a list of drives:
Dim drives As System.Collections.ObjectModel.ReadOnlyCollection(Of IO.DriveInfo) = My.Computer.FileSystem.Drives
Dim rootDir As String = String.Empty

'Now loop thru each drive and populate the treeview:
For i As Integer = 0 To drives.Count - 1
  System.Windows.Forms.Application.DoEvents()

  rootDir = drives(i).Name

  'Add this drive as a root node:
  TreeView1.Nodes.Add(rootDir)

  'Populate this root node:
  PopulateTreeView(rootDir, TreeView1.Nodes(i))

NextDrive:
Next i

End Sub

Private Sub PopulateTreeView(ByVal dir As String, ByVal parentNode As TreeNode)
Dim folder As String = String.Empty

Try
  Dim folders() As String = IO.Directory.GetDirectories(dir)

  If folders.Length <> 0 Then
    Dim childNode As TreeNode = Nothing

    For Each folder In folders
      System.Windows.Forms.Application.DoEvents()

      childNode = New TreeNode(folder)
      parentNode.Nodes.Add(childNode)
      PopulateTreeView(folder, childNode)
    Next folder
  End If

Catch ex As System.IO.IOException
  parentNode.Nodes.Add(folder & ": Drive not Ready")

Catch ex As UnauthorizedAccessException
  parentNode.Nodes.Add(folder & ": Access Denied")
End Try

End Sub

Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect

If Text <> String.Empty Then
  Dim arr As TreeNode() = TreeView1.Nodes.Find("Client Supplied Files", True)

  For i = 0 To arr.Length - 1
    TreeView1.SelectedNode = arr(i)
  Next
End If

End Sub

End Class

Lost User

Unless some other members beats me to it, I'll write a search-implementation tomorrow. Now, :zzz:

treddie

Thank you very much, and no rush.

JR212

Here is a code that I made by several examples that I found:

Public Class cTreeviewFind
Inherits TreeView
#Region "Functions"
Function SearchTree(ByVal root As TreeNode, ByVal text As String) As System.Collections.Generic.List(Of TreeNode)
Dim nodes As New System.Collections.Generic.List(Of TreeNode)()

  ' case insensitive
  If root.Text.ToUpper().Contains(text.ToUpper()) Then
    nodes.Add(root)
  End If

  For Each node As TreeNode In root.Nodes
    Dim subNodes As System.Collections.Generic.List(Of TreeNode) = SearchTree(node, text)
    If (subNodes.Count > 0) Then
      nodes.AddRange(subNodes)
    End If
  Next
  Return nodes
End Function

''' ''' Zoek in welke node een tekst voorkomt
''' 
''' 
''' 
''' 
''' 
''' 
''' 
Public Function FindNode(ByVal \_nodeCollection As TreeNode, ByVal SearchVal As String, Optional ByVal CaseSensitief As Boolean = False, Optional ByVal CompleteValue As Boolean = False, Optional ByVal refind As Boolean = False) As TreeNode
  Dim tmpNode As TreeNode = Nothing
  Static bFoundSelectedNode As Boolean
  If refind Then bFoundSelectedNode = False
  If Me.SelectedNode.Equals(Me.Nodes(0)) Then
    bFoundSelectedNode = True
  End If
  For Each \_c As TreeNode In \_nodeCollection.Nodes
    If \_c.Equals(Me.SelectedNode) Then
      bFoundSelectedNode = True
    End If
    If bFoundSelectedNode = False Then
      If \_c.Nodes.Count > 0 Then
        tmpNode = FindNode(\_c, SearchVal, CaseSensitief, CompleteValue)
        If bFoundSelectedNode = True AndAlso Not tmpNode Is Nothing Then
          Return tmpNode
        End If
      End If
    Else
      If CaseSensitief Then
        If CompleteValue Then
          If \_c.Text = SearchVal AndAlso \_c.Equals(Me.SelectedNode) = False Then Return \_c
          If \_c.Nodes.Count > 0 Then tmpNode = FindNode(\_c, SearchVal, CaseSensitief, CompleteValue)
          If Not tmpNode Is Nothing Then
            Return tmpNode
          End If
        Else
          If \_c.Text.IndexOf(SearchVal) >= 0 AndAlso \_c.Equals(Me.SelectedNode) = False Then Return \_c
          If \_c.Nodes.Count

treddie

FINALLY! One that actually works! :). Now the big $30,000 question is, why doesn't the method that MS and so many others suggest NOT work? Me.TreeView1.SelectedNode = Me.TreeView1.Nodes.Find("Client Supplied Files", True)

Lost User

treddie wrote:

Now the big $30,000 question is, why doesn't the method that MS and so many others suggest NOT work?

Here's a free answer to an expensive question; due to the difference between the nodes' key and it's label. The "find" method works on keys[^] (the name of the node), not on the text being displayed. If you only pass a single string when creating a node, it will not have a name. Try the example below and play a bith with it.

Imports System.Windows.Forms
Module Module1
Private TreeView1 As New TreeView()
Sub Main()
Using f As New Form
Dim btn As New Button
btn.Dock = DockStyle.Top
AddHandler btn.Click, Sub(s As Object, e As EventArgs)
Dim foundNodes As TreeNode() = TreeView1.Nodes.Find("Node 39", True)
If foundNodes.Length > 0 Then
TreeView1.SelectedNode = foundNodes(0)
TreeView1.Focus()
End If
End Sub
TreeView1.Dock = DockStyle.Fill
For i As Integer = 0 To 40
Dim key As String = String.Format("Node {0}", i)
Dim label As String = String.Format("Label {0}", i)
TreeView1.Nodes.Add(key, label)
Next
f.Controls.Add(TreeView1)
f.Controls.Add(btn)
f.ShowDialog()
End Using
End Sub
End Module

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^]

treddie

Heheh...Your code threw me for a second. It looks like you did a C#-to-vb conversion. :) But I figured it out and made the mods to get it to work in vb.Net. (I'm not a "C" guy). Here is my change to your translation, with a caption added to the button:

Imports System.Windows.Forms

Module Module1
Dim TreeView1 As New TreeView

Sub Main()
'This demo is a test of how a TreeView search behaves for a node name (key) vs. the TEXT of the node as
'seen in the TreeView. Searching for the text will fail. YOU NEED THE NAME (KEY) TO DO THE SEARCH.

Using f As New Form
  Dim btn As New Button

  btn.Dock = DockStyle.Top
  btn.Text = "Find ""Label 39"""

  AddHandler btn.Click, AddressOf BClick
  TreeView1.Dock = DockStyle.Fill

  For i As Integer = 0 To 40
    Dim key As String

    'Comment-out this line, and the search will fail,
    'because a node's NAME (its KEY) is NOT its TEXT LABEL!:
    key = String.Format("Node {0}", i)

    Dim label As String = String.Format("Label {0}", i)
    TreeView1.Nodes.Add(key, label)
  Next i

  f.Controls.Add(TreeView1)
  f.Controls.Add(btn)
  f.ShowDialog()

End Using

End Sub

Private Sub BClick(ByVal s As Object, ByVal e As EventArgs)
Dim foundNodes As TreeNode() = TreeView1.Nodes.Find("Node 39", True)
If foundNodes.Length > 0 Then
TreeView1.SelectedNode = foundNodes(0)
TreeView1.Focus()
End If

End Sub

End Module

This makes complete sense now...The name/key is NOT the text label. Although it is best to make sure the key = text, so that you don't get confused by the results.

Lost User

treddie wrote:

It looks like you did a C#-to-vb conversion. :)

Thanks; no conversion, it was a new console-application in the VS-IDE :)

treddie

I'm curious what that app is?

Lost User

VS-IDE? Visual Studio 2010.

treddie

Hm, I'll check out the console part. Thanks for all your help, Eddy!

Lost User

treddie wrote:

Thanks for all your help, Eddy!

My pleasure, glad I could help a bit :)

Bastard Programmer from Hell :suss: If you can't read my code, try converting it here[^]