Conversion obscurities for a newb

[Chris Wills]

I am sorry, but I am learning VB-NET (very slowly), and I wanted a function to do a recursive search, so I imported one I found on http://www.planetsourcecode.com/ that I had been told about. But in the conversion, it came up with a couple of errors that I am really out of my depth with. Can anyone help me.

THE OFFENDING PORTION OF CODE

    Public Function GetFolder(ByRef hWnd As Integer, Optional ByRef sPrompt As String = "", Optional ByRef sStartFolder As String = "") As String
        '##############################################################################################
        'Displays a Folder Browser to select a Folder
        '##############################################################################################
 
        Dim BI As BROWSEINFO
        Dim pidl As Integer
        Dim sFolder As String
        Dim pos As Short
 
        'Fill the BROWSEINFO structure with the needed data
        With BI
            'hwnd of the window that receives messages from the call. Can be your application or the handle from GetDesktopWindow().
            .hOwner = hWnd
 
            'Pointer to the item identifier list specifying the location of the "root" folder to browse from.
            'If NULL, the desktop folder is used.
            .pidlRoot = 0
 
            'message to be displayed in the Browse dialog
            If Len(sPrompt) = 0 Then
                .lpszTitle = "Select the folder:"
            Else
                .lpszTitle = sPrompt
            End If
 
            'the type of folder to return. - the constants perform differently for non networked pc's
            .ulFlags = BIF_RETURNONLYFSDIRS
 
            'UPGRADE_WARNING: Add a delegate for AddressOf BrowseCallbackProc Click for more: 'ms-help://MS.VSCC.v90/dv_commoner/local/redirect.htm?keyword="E9E157F7-EF0C-4016-87B7-7D7FBBC6EE08"'
            .lpfn = FARPROC(AddressOf BrowseCallbackProc)
            'UPGRADE_ISSUE: Constant vbUnicode was not upgraded. Click for more: 'ms-help://MS.VSCC.v90/dv_commoner/local/redirect.htm?keyword="55B59875-9A95-4B71-9D6A-7C294BF7139D"'
            .lParam = SHSimpleIDListFromPath(StrConv(sStartFolder, vbUnicode))
        End With
 
        'show the browse for folders dialog
        pidl = SHBrowseForFolder(BI)
 
        'the dialog has closed, so parse & display the user's returned folder selection contained in pidl
        sFolder = Space(MAX_PATH)
 
        If SHGetPathFromIDList(pidl, sFolder) Then
            pos = InStr(sFolder, Chr(0))
            GetFolder = Left(sFolder, pos - 1)
        End If
 
        Call CoTaskMemFree(pidl)
    End Function

Thank you

Chris

[tlhintoq]

So in the end you're saying you want to browse files and folder recursively.
Same topic in C# with links to the MSDN tutorial.

TIP: When you are writing your question, there is a button on the tool bar that wraps the [code] tags around your copy/pasted code. It helps a bunch. Its the button with a '#' on it. More on tags. They're cool. Check'em out.

[Chris Wills]

Thank you for the quick reply.

And sorry, I didn't know about the # - but I do now!! :) I will check out the link.

[tlhintoq]

@Chris Wills
Yeah, a button with '#' on it doesn't intuitively scream out "Wrap with code tags" - Unless maybe you are working in C#

[Chris Wills]

I read the article in MSDN and that seems to work quite well, except that it does raise a couple of points.

The first is that it only seems to work for "C:\Documents an Settings\", and not for any other directory that I may set.

And the second is that it doesn't always seem to "Initialise"?

Imports System.IO
 
Public Class Form1
 
    Public Sub New()
        InitializeComponent()
        PopulateTreeView()
 
    End Sub 'New
 
    Private Sub treeView1_NodeMouseClick(ByVal sender As Object, ByVal e As TreeNodeMouseClickEventArgs) Handles TreeView1.NodeMouseClick
 
        Dim newSelected As TreeNode = e.Node
        ListView1.Items.Clear()
        Dim nodeDirInfo As DirectoryInfo = CType(newSelected.Tag, DirectoryInfo)
        Dim subItems() As ListViewItem.ListViewSubItem
        Dim item As ListViewItem = Nothing
 
        Dim dir As DirectoryInfo
        For Each dir In nodeDirInfo.GetDirectories()
            item = New ListViewItem(dir.Name, 0)
            subItems = New ListViewItem.ListViewSubItem() {New ListViewItem.ListViewSubItem(item, "Directory"), New ListViewItem.ListViewSubItem(item, dir.LastAccessTime.ToShortDateString())}
 
            item.SubItems.AddRange(subItems)
            ListView1.Items.Add(item)
        Next dir
        Dim file As FileInfo
        For Each file In nodeDirInfo.GetFiles()
            item = New ListViewItem(file.Name, 1)
            subItems = New ListViewItem.ListViewSubItem() {New ListViewItem.ListViewSubItem(item, "File"), New ListViewItem.ListViewSubItem(item, file.LastAccessTime.ToShortDateString())}
            item.SubItems.AddRange(subItems)
            ListView1.Items.Add(item)
        Next file
 
        ListView1.AutoResizeColumns(ColumnHeaderAutoResizeStyle.HeaderSize)
 
    End Sub
 
    Private Sub PopulateTreeView()
        Dim rootNode As TreeNode
        Dim info As New DirectoryInfo("C:\Documents and Settings\")
        'Dim info As New DirectoryInfo("C:\Program Files\")
        If info.Exists Then
            rootNode = New TreeNode(info.Name)
            rootNode.Tag = info
            GetDirectories(info.GetDirectories(), rootNode)
            TreeView1.Nodes.Add(rootNode)
        End If
 
    End Sub
 
    Private Sub GetDirectories(ByVal subDirs() As DirectoryInfo, _
        ByVal nodeToAddTo As TreeNode)
 
        Dim aNode As TreeNode
        Dim subSubDirs() As DirectoryInfo
        Dim subDir As DirectoryInfo
        For Each subDir In subDirs
            aNode = New TreeNode(subDir.Name, 0, 0)
            aNode.Tag = subDir
            aNode.ImageKey = "folder"
            subSubDirs = subDir.GetDirectories()
            If subSubDirs.Length <> 0 Then
                GetDirectories(subSubDirs, aNode)
            End If
            nodeToAddTo.Nodes.Add(aNode)
        Next subDir
 
    End Sub
 
End Class

Thanks

Chris

[tlhintoq]

I read the article in MSDN and that seems to work quite well, except that it does raise a couple of points.

The first is that it only seems to work for "C:\Documents an Settings\", and not for any other directory that I may set.

And the second is that it doesn't always seem to "Initialise"?

A) other directories. That seems very unlikely. I use this kind of thing all the time. Is it possible you are setting paths to directories that you don't have permissions to, or have typos in the paths just like you did above? You should try a test with a simple path that you make first. "C:\test\" for example

B) You don't have an "Initialise" method in your code. So what is is you are saying doesn't happen consistently. Have you tried putting a breakpoint in the method you feel isn't always working and stepping through it line by line to see under what conditions it does something you don't expect?

[Chris Wills]

@tlhintoq
The code may have gotten missed as I had to save the text in Notepad, as I have been trying to post back here since Friday, and it always "bombed on submission. IE had somehow set to debug scripts and that caused it.

To A).- This code seems to work normally so long as it is working with line 41 "C:\Documents and Settings" in the above code. But if I "comment out" line 41 and substitute line 42, then nothing happens. (I am running as Administrator on this machine on XP, not Vista). Any other Drive or directory it just seems to sit there?

To B).- I wanted this initialisation to happen during loading of the form and I think I'd read, probably wrongly that that was what line 6 should do.

PS: Sorry to be such a "plank", perhaps the old DOS days of Basic spoilt me. Now retired, I am purely attempting VB as an interest, which I hope to use in my hobby.

[tlhintoq]

Comment out line 41.
Restore line 42
Put a breakpoint on line 40

When the code stops on line 40 use the f-10 key to walk through the code one line at a time.
After it has moved to line 43 you can hover your mouse over any occurence of the variable "info" and the pop-up tooltips will show you its values.

This way you can see if you are getting any values for this.

[Chris Wills]

I can at last see an end to this, as yesterday I deliberately re-built the form and code, and found that the reason for my thinking that it was broken for anything but "Documents and Settings" was the fact that not only was the treeview disappearing somtimes, but also, to read "Program Files" for example, it took a very measurable amount of time (about 1 min) before it decided to display.

So I guess I'll have to find something a bit quicker.

[tlhintoq]

That is the issue with pre-loading the entire directory structure and all the subdirectories at once.

Since you are doing this in a treeview might I suggest that you only populate one level of hierarchy at a time?

You can get all of the folders at "C:\Programs" and put those into your treeview quickly.

Then when the user opens a node, load just the next level of just that folder. It will also go quickly.

That way you don't waste time loading 500 folders of data the user isn't going to go to anyway.

[Chris Wills]

@tlhintoq
Oh OK, never thought of that!! haha

Anyway thanks very much for all your help, thank you.