Capture Windows Form close event in Powershell - winforms

Question

I have a windows form. When I click on the close (X) button of the Windows Form Control Box, I want to display a message or may be do something.
Below is the code:
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing")
[void] [System.Windows.Forms.Application]::EnableVisualStyles()
$frmTest = New-Object System.Windows.Forms.Form
$frmTest.Size = New-Object System.Drawing.Size(640,480)
$frmTest.MaximizeBox = $False
$frmTest.ShowDialog()
When the user clicks on the Close (X) button, I want to display a message box:
$choice = [System.Windows.Forms.MessageBox]::Show('Are you you want to exit?','TEST','YesNo','Error')
switch($choice)
{
'Yes'
{
$frmTest.Close()
}
}
I found this article: Message on Form Close, but I am not sure how to use this. Please advice. Thanks

Answer 1

The event to capture is Closing event of the form which has an event argument which allows you to cancel the event. To learn how to use event args in PowerShell, you may want to take a look at Windows Forms Controls Events in PowerShell - Use Sender and EventArgs.
Example
Add-Type -AssemblyName System.Windows.Forms
$form = New-Object System.Windows.Forms.Form
$form.Text ="Test"
$form.Add_Closing({param($sender,$e)
$result = [System.Windows.Forms.MessageBox]::Show(`
"Are you sure you want to exit?", `
"Close", [System.Windows.Forms.MessageBoxButtons]::YesNoCancel)
if ($result -ne [System.Windows.Forms.DialogResult]::Yes)
{
$e.Cancel= $true
}
})
$form.ShowDialog() | Out-Null
$form.Dispose()