Powershell dialog box with countdown and option to press cancel? - powershell

Question

I have been trying to create a Powershell script that performs the following
Shows a dialog box that an update is about to occur
Provide a countdown of say 30 seconds
During the countdown, a user can press "Cancel Update"
If the countdown expires and "Cancel Update" was not pressed, then update will occur
Right before the loop, the window shows if I call $Counter_Form.ShowDialog() and I can click the Cancel button. When clicking, the following should occur.
Window should close after pressing the button. This is correct.
$cancel should be set to $true to indicate that Cancel was pressed. However, it remains $false and this is incorrect. Why is this?
Now, for the problems in the while loop
The window refreshes to show the new delay, but I cannot click "Cancel Update" since it just shows an hourglass icon and seems to be frozen
Script
#Adjust delay here
$delay = 5
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
$Counter_Form = New-Object System.Windows.Forms.Form
$Counter_Form.Text = "Warning"
#Form size options
$Counter_Form.Width = 350
$Counter_Form.Height = 150
#Centers form on screen
$Counter_Form.StartPosition = "CenterScreen"
#Places form on top of everything else
$Counter_Form.TopMost = $true
$Counter_Label = New-Object System.Windows.Forms.Label
$Counter_Label2 = New-Object System.Windows.Forms.Label
#Label2's text
$Counter_Label2.Text = "Please save all your work"
#Labels size and position
$Counter_Label.AutoSize = $true
$Counter_Label.Location = New-Object System.Drawing.Point(50,60)
$Counter_Label2.AutoSize = $true
$Counter_Label2.Location = New-Object System.Drawing.Point(90,30)
$cancel = $false
$button1 = New-Object System.Windows.Forms.Button
$button1.Text = "Cancel Update";
$button1.Location = New-Object System.Drawing.Point(130,80)
$button1.Add_Click({ $Counter_Form.Close(); $cancel = $true})
$Counter_Form.Controls.Add($Counter_Label)
$Counter_Form.Controls.Add($Counter_Label2)
$Counter_Form.Controls.Add($button1)
#LOOP!
while ($delay -ge 0 -And $cancel -eq $false)
{
$Counter_Form.Show()
#Timer label's text
$Counter_Label.Text = "Update will occur in $($delay) seconds."
start-sleep 1
$delay -= 1
}
$Counter_Form.Close()

Answer 1

For the first question about $cancel not being updated to $true, it is a result of scope.
Add the script scope, with $script:cancel = $true. So that line of code should be:
$button1.Add_Click({ $Counter_Form.Close(); $script:cancel = $true})
I didn't find an exact solution to what I started. A pieced together some code from various sources and found the following worked. I'm posting it here in case it ends up helping someone:
function ShowMsg ($timeout, $message)
{
Add-Type -AssemblyName system.windows.forms
Add-Type -AssemblyName system.drawing
$form = New-Object System.Windows.Forms.Form
$form.Text = "Window Title"
$form.Size = New-Object System.Drawing.Size(300,300)
$form.StartPosition = 'CenterScreen'
$label = New-Object System.Windows.Forms.label
$label.Text = $message
$label.Size = New-Object System.Drawing.Size(280,205)
$form.Controls.Add($label)
#add button to form
$okButton = New-Object System.Windows.Forms.Button
$okButton.Location = New-Object System.Drawing.Point(160,215)
$okButton.Size = New-Object System.Drawing.Size(100,23)
$okButton.Text = 'Cancel Update'
$okButton.DialogResult = [System.Windows.Forms.DialogResult]::OK
$form.AcceptButton = $okButton
$form.Controls.Add($okButton)
$cancelButton = New-Object System.Windows.Forms.Button
$cancelButton.Location = New-Object System.Drawing.Point(40,215)
$cancelButton.Size = New-Object System.Drawing.Size(100,23)
$cancelButton.Text = 'Allow Update'
$cancelButton.DialogResult = [System.Windows.Forms.DialogResult]::CANCEL
$form.CancelButton = $cancelButton
$form.Controls.Add($cancelButton)
$timer = New-Object System.Windows.Forms.Timer
$timer.Interval = $timeout * 1000
$timer.add_tick({$form.Close()})
$timer.Start()
$form.Topmost = $true
$form.ShowDialog()
$form.Dispose()
}
Calling the function:
$timeout = 60 #seconds
$message_response = ShowMsg -timeout $timeout -message "Hello, update is happening"