Find files with filename filter - vb.net

Question

I am using VB.net VS2012 and am having trouble with getting a list of files with a filter.
Here is my code:
Public Function SearchAndAddToListWithFilter(ByVal path As String, ByVal Recursive As Boolean, arrayListOfFilters As ArrayList, ByRef listOfFiles As List(Of FileInfo))
If Not Directory.Exists(path) Then Exit Function
Dim initDirInfo As New DirectoryInfo(path)
For Each oFileInfo In initDirInfo.GetFiles
Application.DoEvents()
For x = 0 To arrayListOfFilters.Count - 1
If (oFileInfo.Name Like arrayListOfFilters(x)) Then
listOfFiles.Add(oFileInfo)
End If
Next
Next
If Recursive Then
For Each oDirInfo In initDirInfo.GetDirectories
SearchAndAddToListWithFilter(oDirInfo.FullName, True, arrayListOfFilters, listOfFiles)
Next
End If
End Function
And here is an example of how to use it:
Dim stringFilterList As String = "*.mp3, *.docx, *.mp3, *.txt"
Dim arrayListOfFilenameFilters As New ArrayList(stringFilterList.Split(","))
Dim stringFolderPath As String = "C:\temp\folder\"
Dim booleanSearchSubFolders As Boolean = True
Dim listOfFilesFoundViaSearch As New List(Of FileInfo)
SearchAndAddToListWithFilter(stringFolderPath, booleanSearchSubFolders, arrayListOfFilenameFilters, listOfFilesFoundViaSearch)
For x = 0 To listOfFilesFoundViaSearch.Count - 1
MsgBox(listOfFilesFoundViaSearch(x).FullName)
Next
For some reason, the code only adds the files to the list that satisy the first condition in the list of filters.
Can I please have some help to get this code working?
Thank you.

Answer 1

Functions return values, and passing a value ByRef is NOT the way to do it.
The following function will work:
Private Function SearchAndAddToListWithFilter(ByVal path As String, ByVal filters As String(), ByVal searchSubFolders As Boolean) As List(Of IO.FileInfo)
If Not IO.Directory.Exists(path) Then
Throw New Exception("Path not found")
End If
Dim searchOptions As IO.SearchOption
If searchSubFolders Then
searchOptions = IO.SearchOption.AllDirectories
Else
searchOptions = IO.SearchOption.TopDirectoryOnly
End If
Return filters.SelectMany(Function(filter) New IO.DirectoryInfo(path).GetFiles(filter, searchOptions)).ToList
End Function
and to use this function:
Dim filters As String() = {"*.mp3", "*.docx", "*.bmp", "*.txt"}
Dim path As String = "C:\temp\folder\"
Dim foundFiles As List(Of IO.FileInfo) = SearchAndAddToListWithFilter(path, filters, True)

Answer 2

The solution provided by #Steve really shows the .NET way of doing the task.
However I used a recursive solution with possible definitions of maximum depth and/or duration. For completeness of this topic, I want to post the code:
''' <summary>
''' Search files in directory and subdirectories
''' </summary>
''' <param name="searchDir">Start Directory</param>
''' <param name="searchPattern">Search Pattern</param>
''' <param name="maxDepth">maximum depth; 0 for unlimited depth</param>
''' <param name="maxDurationMS">maximum duration; 0 for unlimited duration</param>
''' <returns>a list of filenames including the path</returns>
''' <remarks>
''' recursive use of Sub dirS
'''
''' wallner-novak#bemessung.at
''' </remarks>
Public Shared Function dirRecursively(searchDir As String, searchPattern As String, _
Optional maxDepth As Integer = 0, _
Optional maxDurationMS As Long = 0) As List(Of String)
Dim fileList As New List(Of String)
Dim depth As Integer = 0
Dim sw As New Stopwatch
dirS(searchDir, searchPattern, maxDepth, maxDurationMS, fileList, depth, sw)
Return fileList
End Function
''' <summary>
''' Recursive file search
''' </summary>
''' <param name="searchDir">Start Directory</param>
''' <param name="searchPattern">Search Pattern</param>
''' <param name="maxDepth">maximum depth; 0 for unlimited depth</param>
''' <param name="maxDurationMS">maximum duration; 0 for unlimited duration</param>
''' <param name="fileList">Filelist to append to</param>
''' <param name="depth">current depth</param>
''' <param name="sw">stopwatch</param>
''' <param name="quit">boolean value to quit early (at given depth or duration)</param>
''' <remarks>
''' wallner-novak#bemessung.at
''' </remarks>
Private Shared Sub dirS(searchDir As String, searchPattern As String, _
Optional maxDepth As Integer = 0, _
Optional maxDurationMS As Long = 0, _
Optional ByRef fileList As List(Of String) = Nothing, _
Optional ByRef depth As Integer = 0, _
Optional ByRef sw As Stopwatch = Nothing, _
Optional ByRef quit As Boolean = False)
If maxDurationMS > 0 Then
If depth = 0 Then
sw = New Stopwatch
sw.Start()
Else
If sw.ElapsedMilliseconds > maxDurationMS Then
quit = True
Exit Sub
End If
End If
End If
If maxDepth > 0 Then
If depth > maxDepth Then
quit = True
Exit Sub
End If
End If
' check if directory exists
If Not Directory.Exists(searchDir) Then
Exit Sub
End If
' find files
For Each myFile As String In Directory.GetFiles(searchDir, searchPattern)
fileList.Add(myFile)
Next
' recursively scan subdirectories
For Each myDir In Directory.GetDirectories(searchDir)
depth += 1
dirS(myDir, searchPattern, maxDepth, maxDurationMS, fileList, depth, sw, quit)
If quit Then Exit For
depth -= 1
Next
End Sub

Answer 3

ListView1.Items.Clear()
For Each files As String In System.IO.Directory.GetFiles(cmb_Drives.SelectedItem.ToString, txtSearch.Text)
Dim ico As Icon = System.Drawing.Icon.ExtractAssociatedIcon(files)
ImageList1.Images.Add(ico)
Dim list As ListViewItem = New ListViewItem(My.Computer.FileSystem.GetFileInfo(files).FullName, ImageList1.Images.Count - 1)
ListView1.Items.Add(list)
Next