Locked files from one of the system.io classes - vb.net

Question

I am trying to develop a simple bulk copy program that polls a given folder for files at specified intervals.
The code looks perfect. My output gives a great recursive list of files, but when I go to actually move them according to the list, every file I scanned is locked. I have tried garbage collecting, disposing, exiting subs at certain points, debugging at certain points...
Please take a look at my code. When MoveFile is called, everything is locked.
Imports System
Imports System.IO
Public Structure FileStructure
Dim Enumerator As Integer
Dim SPath As String
Dim DPath As String
Dim Name As String
Dim FileSize As Long
Dim IsFile As Short
Dim SourceFullName As String
Dim DestFullName As String
End Structure
Public Class StagingDriveCoordinator
Dim FilesScanned As FileStructure()
Dim ScanCount As Integer = -1
Private Sub ScanAll(ByVal sourcePath As String, ByVal destinationPath As String)
Dim sourceDirectoryInfo As New System.IO.DirectoryInfo(sourcePath)
' ---------------------- Create the appropriate directories --------------------------------
' Create source path
If Not System.IO.Directory.Exists(sourcePath) Then
System.IO.Directory.CreateDirectory(sourcePath)
End If
' If the destination folder doesn't exist then create it
If Not System.IO.Directory.Exists(destinationPath) Then
System.IO.Directory.CreateDirectory(destinationPath)
End If
' ------------------------------------------------------------------------------------------
Dim AddSize As Integer = 0
'Figure out how much to resize the array this iteration of ScanAll
If FilesScanned IsNot Nothing Then
AddSize = FilesScanned.Count + sourceDirectoryInfo.GetFileSystemInfos.Length
Else
AddSize = sourceDirectoryInfo.GetFileSystemInfos.Length
End If
'Resize the array
Array.Resize(FilesScanned, AddSize)
For Each FileSystemInfo In sourceDirectoryInfo.GetFileSystemInfos
ScanCount += 1
FilesScanned(ScanCount).Enumerator = ScanCount
FilesScanned(ScanCount).SPath = sourcePath.ToString
FilesScanned(ScanCount).DPath = destinationPath.ToString
FilesScanned(ScanCount).Name = FileSystemInfo.Name.ToString
If TypeOf FileSystemInfo Is System.IO.FileInfo Then
FilesScanned(ScanCount).FileSize = DirectCast(FileSystemInfo, FileInfo).Length
FilesScanned(ScanCount).IsFile = 1
Else
FilesScanned(ScanCount).FileSize = 9223372036854775807
FilesScanned(ScanCount).IsFile = 0
End If
FilesScanned(ScanCount).SourceFullName = System.IO.Path.Combine(sourcePath, FileSystemInfo.Name).ToString
FilesScanned(ScanCount).DestFullName = System.IO.Path.Combine(sourcePath, FileSystemInfo.Name).ToString
txtOutput.Text += FilesScanned(ScanCount).Enumerator & vbTab & FilesScanned(ScanCount).SourceFullName & vbNewLine
If FilesScanned(ScanCount).IsFile = 0 Then
'Debug
txtOutput.Text += vbNewLine & "Recursively scanning subfolder " + FilesScanned(ScanCount).Name & "..." + vbNewLine + vbNewLine
'Recursively call the main scanner.
ScanAll(FilesScanned(ScanCount).SourceFullName, FilesScanned(ScanCount).DestFullName)
End If
Next
End Sub
Private Sub MoveFile(ByVal Source, ByVal Destination, ByVal filesize)
Try
File.Copy(Source, Destination, True)
txtOutput.Text += "Moving file... Source: " & Source & ". Filesize: " & filesize.ToString & vbNewLine
txtOutput.Text += "Destination: " & Destination & vbNewLine & vbNewLine
File.Delete(Source)
Catch ex As Exception
txtOutput.Text += "File " & Source & " is locked." & vbNewLine
End Try
End Sub
Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
Select Case cmbPollingFrequency.SelectedItem
Case "5 Seconds"
Timer1.Interval = 5000
Case "30 Seconds"
Timer1.Interval = 30000
Case "1 Minute"
Timer1.Interval = 60000
Case "5 Minutes"
Timer1.Interval = 300000
Case "15 Minutes"
Timer1.Interval = 900000
Case "30 Minutes"
Timer1.Interval = 1800000
Case "1 Hour"
Timer1.Interval = 3600000
Case Else
MsgBox("You must select an interval.")
End Select
Timer1.Start()
End Sub
Private Sub TimerTick(sender As Object, e As EventArgs) Handles Timer1.Tick
Timer1.Stop()
txtOutput.Text += DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss") & vbNewLine
txtOutput.Text += "Scanning Filesystem..." + vbNewLine + vbNewLine
'Scan the file system.
ScanAll(cmbStaging.Text, cmbBackup.Text)
txtOutput.Text += vbNewLine
txtOutput.Text += DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss") & vbNewLine
txtOutput.Text += " ------------- Scan cycle completed. --------------- " & vbNewLine & vbNewLine
txtOutput.Text += "Sorting by filesize..." & vbNewLine & vbNewLine
' Sort the file list by size.
FilesScanned = FilesScanned.OrderBy(Function(x) x.FileSize).ToArray
txtOutput.Text += "Done." & vbNewLine & vbNewLine
txtOutput.Text += "Moving smallest files first..." & vbNewLine & vbNewLine
For Each FileElement In FilesScanned
If FileElement.IsFile > 0 Then
'file.FileSize only needed to pass size to text output
MoveFile(FileElement.SourceFullName, FileElement.DestFullName, FileElement.FileSize)
End If
Next
FilesScanned = Nothing
ScanCount = -1
Timer1.Start()
End Sub
Private Sub btnStop_Click(sender As Object, e As EventArgs) Handles btnStop.Click
Timer1.Stop()
End Sub
End Class

Answer 1

I found the problem. The IO system was NOT locking the file. I was trying to copy it to the SAME directory...
FilesScanned(ScanCount).SourceFullName =
System.IO.Path.Combine(sourcePath, FileSystemInfo.Name).ToString
FilesScanned(ScanCount).DestFullName =
System.IO.Path.Combine(sourcePath, FileSystemInfo.Name).ToString
This should have been:
FilesScanned(ScanCount).SourceFullName =
System.IO.Path.Combine(sourcePath, FileSystemInfo.Name).ToString
FilesScanned(ScanCount).DestFullName =
System.IO.Path.Combine(destinationPath, FileSystemInfo.Name).ToString
Once I changed it, everything worked perfectly.