Copying same file to multiple locations / drives with progress bar - vb.net

Question

I am trying to make a vb.net appliaction designed to copy one file to multiple locations at the same time. But I can't figure out how to stop the System.IO.IOException I am receiving because multiple threads are trying to access the file. Here is my current code:
Dim parts As String() = targ.Split(New Char() {"\"c})
Dim filename As String = parts(parts.Count - 1) 'target folder name
Dim dir_path As String = "" 'directory without target folder name
Dim FolderList As New List(Of String)
Dim copied As Integer = 0<
For f As Integer = 0 To parts.Count - 2
dir_path += parts(f) + "\"
Next
Dim counter As Integer = IO.Directory.GetFiles(targ, "*.*", IO.SearchOption.AllDirectories).Length 'counts the number of files
newitm.SubItems(4).Text = "Copied (0/" + counter.ToString + ")" 'displays the amount of copied files
FolderList.Add(targ) 'Set first folder
Do While True
Dim FoldersInsideDirectory As New List(Of String)
If FolderList.Count = 0 Then
Exit Do 'If there is no folder to copy Exit Do
Else
For l As Integer = 0 To FolderList.Count - 1
Dim fileSystemInfo As System.IO.FileSystemInfo
Dim sourceDirectoryInfo As New System.IO.DirectoryInfo(FolderList(l))
Dim dest As String = FolderList(l).Replace(dir_path, "")
If (Not System.IO.Directory.Exists(des + "\" + dest)) Then 'create subFolder inside directory
System.IO.Directory.CreateDirectory(des + "\" + dest)
End If
For Each fileSystemInfo In sourceDirectoryInfo.GetFileSystemInfos
Dim destinationFileName As String = System.IO.Path.Combine(des + "\" + dest, fileSystemInfo.Name)
If TypeOf fileSystemInfo Is System.IO.FileInfo Then
Dim streamRead As New System.IO.FileStream(fileSystemInfo.FullName, System.IO.FileMode.Open)
Dim streamWrite As New System.IO.FileStream(des + "\" + dest + "\" + fileSystemInfo.Name, IO.FileMode.Create, IO.FileAccess.Write, IO.FileShare.None)
Dim lngLen As Long = streamRead.Length - 1
newitm.SubItems(3).Text = "Copy bytes : (0/" + (lngLen * 100).ToString + ")"
Dim byteBuffer(1048576) As Byte 'our stream buffer
Dim intBytesRead As Integer 'number of bytes read
While streamRead.Position < lngLen 'keep streaming until EOF
newitm.SubItems(3).Text = "Copy bytes : (" + CInt(streamRead.Position).ToString + "/" + (lngLen * 100).ToString + ")"
intBytesRead = (streamRead.Read(byteBuffer, 0, 1048576))
streamWrite.Write(byteBuffer, 0, intBytesRead)
streamRead.Flush()
End While
'Clean up
streamWrite.Flush()
streamWrite.Close()
streamRead.Close()
copied += 1
newitm.SubItems(4).Text = "Copied (" + copied.ToString + "/" + counter.ToString + ")"
Else
FoldersInsideDirectory.Add(fileSystemInfo.FullName)
End If
Next
Next
FolderList.Clear()
FolderList = FoldersInsideDirectory
End If
MsgBox("Done")
Loop

Answer 1

You need to specify FileShare.Read in the FileStream's constructor:
Read
Allows subsequent opening of the file for reading. If this flag is not specified, any request to open the file for reading (by this process or another process) will fail until the file is closed.
Dim streamRead As New System.IO.FileStream(fileSystemInfo.FullName, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read)