Powershell ISE form: How to stop Robocopy with function? - winforms

Question

I have a Windows Form created in PowerShell ISE, used to perform robocopy with a button.
It works fine, but the interface hangs when the robocopy is in progress, which I believe to be normal behaviour; something about the tasks running in the same thread.
I want to be able to stop this robocopy process while it is running, I need some help on how to do this.
I created a button and function to do this, I just need help on what to do in the function (and elsewhere if needed).
I've seen someone do this, but it doesn't seem to work for me; it outputs "Robocopy has been terminated" like it's supposed to but continues running through the files:
function start_robocopy {
robocopy "$($InputSource.Text)" "$($InputDestination.Text)" /ndl /e /np /tee /L | ForEach-Object {
[void] [System.Windows.Forms.Application]::DoEvents() }
}
function stop_robocopy {
if (Get-Process -Name robocopy -ErrorAction SilentlyContinue) {Stop-Process -Name robocopy -Force
$outputBox.AppendText("Robocopy has been terminated.")}
My full code here; see function template created at the bottom:
Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()
$form = New-Object System.Windows.Forms.Form
$form.Size = New-Object System.Drawing.Size(850,582)
$form.add_Load($FormEvent_Load)
$outputBox = New-Object System.Windows.Forms.TextBox
$outputBox.Location = New-Object System.Drawing.Size(200,110)
$outputBox.Size = New-Object System.Drawing.Size(620,420)
$outputBox.MultiLine = $True
$outputBox.ScrollBars = "Both"
$outputBox.BackColor = "White"
$outputBox.ReadOnly = $True
$Form.Controls.Add($outputBox)
#-----FORM END-----#
#-----BUTTONS START-----#
$StartBtn = New-Object System.Windows.Forms.Button
$StartBtn.Location = New-Object System.Drawing.Size(10,80)
$StartBtn.Size = New-Object System.Drawing.Size(180,35)
$StartBtn.Text = "Start Robocopy"
$StartBtn.Add_Click({start_robocopy})
$form.Controls.Add($StartBtn)
$StopBtn = New-Object System.Windows.Forms.Button
$StopBtn.Location = New-Object System.Drawing.Size(10,150)
$StopBtn.Size = New-Object System.Drawing.Size(180,35)
$StopBtn.Text = "Stop Robocopy"
$StopBtn.Add_Click({stop_robocopy})
$form.Controls.Add($StopBtn)
#-----BUTTONS END-----#
#-----INPUTBOXES START-----#
$InputSource = New-Object System.Windows.Forms.TextBox
$InputSource.Text="C:\test\src"
$InputSource.Location = New-Object System.Drawing.Size(10,15)
$InputSource.Size = New-Object System.Drawing.Size(140,20)
$form.Controls.Add($InputSource)
$InputDestination = New-Object System.Windows.Forms.TextBox
$InputDestination.Text="C:\test\dst"
$InputDestination.Location = New-Object System.Drawing.Size(10,40)
$InputDestination.Size = New-Object System.Drawing.Size(140,20)
$form.Controls.Add($InputDestination)
#-----INPUTBOXES END-----#
#-----FUNCTIONS START-----#
function start_robocopy {
robocopy "$($InputSource.Text)" "$($InputDestination.Text)" /ndl /e /np /tee /L | ForEach-Object { $outputBox.AppendText($_ + "`r`n") }
}
function stop_robocopy {
#WHAT TO DO HERE?
}
#-----FUNCTIONS END-----#
$form.ShowDialog()

Answer 1

You can use PowerShell background job so that you have control over it and it will not hang the UI.
Use Start-Job and capture the jobId and then use the same jobId to stop the job in stop_robocopy.
function start_robocopy {
$source = Write-Host $InputSource.Text;
$destination = Write-Host $InputDestination.Text;
$jobId = Invoke-Command -ScriptBlock {Start-Job -ScriptBlock { robocopy "$source" "$destination" /ndl /e /np /tee /L | ForEach-Object { $outputBox.AppendText($_ + "`r`n") } }}
$global:newJobId = $jobId.Id
}
function stop_robocopy {
$jobId = Get-Job -Id $newJobId;
Invoke-Command -ScriptBlock { Stop-job -Id $jobId.Id }
Write-Host "Stopped: $($jobId.Id)"
}