Process locking temporary file. How can i get around this? - powershell

Question

As part of looking into creating a GUI for handling certain repetitive tasks i made for for a eight ball function. As part of this function i use an background image and an icon that is embedded in the script and written to $env:tmp.
Upon exit from the GUI i have a cleanup to remove the temporary files. However the script is unable to delete the background image while PowerShell is running even when the form has been terminated.¨
Remove-Item : Cannot remove item C:\Users\USERNAME\AppData\Local\Temp\11a8093b2817a3e1ff135fec4fe01320.jpg: The process cannot access the file 'C:\Users\USERNAME\AppData\Local\Temp\1
1a8093b2817a3e1ff135fec4fe01320.jpg' because it is being used by another process.
At C:\Users\USERNAME\Desktop\8ball.ps1:89 char:1
+ Remove-Item "$env:temp\11a8093b2817a3e1ff135fec4fe01320.jpg"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : WriteError: (C:\Users\USERN~...fec4fe01320.jpg:FileInfo) [Remove-Item], IOException
+ FullyQualifiedErrorId : RemoveFileSystemItemIOError,Microsoft.PowerShell.Commands.RemoveItemCommand
Is there any "simple" way i can get around this?
$MagicEightBallPicture = ""
$ContentPicture = [System.Convert]::FromBase64String($MagicEightBallPicture)
(Set-Content -Path $env:temp\11a8093b2817a3e1ff135fec4fe01320.jpg -Value $ContentPicture -Encoding Byte)
$MagicEightBallIcon = ""
$ContentIcon = [System.Convert]::FromBase64String($MagicEightBallIcon)
(Set-Content -Path $env:temp\11a8093b2817a3e1ff135fec4fe01320.ico -Value $ContentIcon -Encoding Byte)
$PossibleAnswers = #("It is certain",`
"It is decidedly so",`
"Without a doubt",`
"Yes, definitely",`
"You may rely on it",`
"As I see it, yes",`
"Most likely",`
"Outlook good",`
"Yes",`
"Signs point to yes",`
"Reply hazy try again",`
"Ask again later",`
"Better not tell you now",`
"Cannot predict now",`
"Concentrate and ask again",`
"Dont count on it",`
"My reply is no",`
"My sources say no",`
"Outlook not so good",`
"Very doubtful")
Function RollTheBall {
$TheAnswer = Get-Random -Count 1 -InputObject $PossibleAnswers
$TheAnswerBox.Text = $TheAnswer
}
Try {
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
$Image = [System.Drawing.Image]::Fromfile("$($env:temp)\11a8093b2817a3e1ff135fec4fe01320.jpg")
$Icon = New-Object System.Drawing.Icon ("$($env:temp)\11a8093b2817a3e1ff135fec4fe01320.ico")
$Form = New-Object System.Windows.Forms.Form
$Form.Text = "Magic Eight Ball"
$Form.MinimizeBox = $False
$Form.MaximizeBox = $False
$Form.FormBorderStyle = 'Fixed3D'
$Form.SizeGripStyle = "Hide"
$Form.ShowInTaskbar = $False
$Form.StartPosition = "CenterScreen"
$Form.Icon = $Icon
$Form.BackgroundImage = $Image
$Form.BackgroundImageLayout = "None"
$Form.Width = $Image.Width
$Form.Height = $Image.Hight
$Form.Size = New-Object System.Drawing.Size(300,200)
$TheAnswerBox = New-Object System.Windows.Forms.TextBox
$TheAnswerBox.Location = New-Object System.Drawing.Size(10,10)
$TheAnswerBox.Size = New-Object System.Drawing.Size(270,20)
$TheAnswerBox.TextAlign = [System.Windows.Forms.HorizontalAlignment]::Center
$TheAnswerBox.add_GotFocus({[System.Windows.Forms.SendKeys]::Send("{tab}")})
$Form.Controls.Add($TheAnswerBox)
$ButtonRollTheBall = New-Object System.Windows.Forms.Button
$ButtonRollTheBall.Location = New-Object System.Drawing.Size(10,40)
$ButtonRollTheBall.Size = New-Object System.Drawing.Size(130,20)
$ButtonRollTheBall.Text = "Help?!"
$ButtonRollTheBall.Add_Click({RollTheBall})
$Form.Controls.Add($ButtonRollTheBall)
$ButtonExit = New-Object System.Windows.Forms.Button
$ButtonExit.Location = New-Object System.Drawing.Size(150,40)
$ButtonExit.Size = New-Object System.Drawing.Size(130,20)
$ButtonExit.Text = "Exit"
$ButtonExit.Add_Click({$Form.Close()})
$Form.Controls.Add($ButtonExit)
$Form.Add_Shown({$Form.Activate()})
[void] $Form.ShowDialog()
} Finally {
Remove-Item "$env:temp\11a8093b2817a3e1ff135fec4fe01320.jpg"
Remove-Item "$env:temp\11a8093b2817a3e1ff135fec4fe01320.ico"
}
I've removed the embedded pictures due to possible copyright and shear size.

Answer 1

Since the Image returned from [System.Drawing.Image]::Fromfile is disposable, you have to Dispose it to clean up the ressources before you delete it:
$Image.Dispose()