Powershell InputBox (selfmade) only returns "Cancel" - powershell

Question

`In a Powershell project - small GUI with Winforms - I need a passwordbox. I wrote a test-function but cannot manage to get the correct output ... I only get "Cancel"
I get the same result if I do not use
$inpBox.PasswordChar = "*"
[reflection.assembly]::loadwithpartialname("System.Windows.Forms") | Out-Null
[reflection.assembly]::loadwithpartialname("System.Drawing") | Out-Null
[System.Windows.Forms.Application]::EnableVisualStyles()
function InputForm {
param($loggedInUser="Spock")
$inpForm = New-Object System.Windows.Forms.Form
$inpForm.Height = 120
$inpForm.Width = 350
# $inpForm.Icon = "$PSScriptRoot\Heidelberg-H.ico"
$inpForm.Text = "Authentication Window"
$inpForm.MaximizeBox = $false
$inpForm.MinimizeBox = $false
$inpForm.FormBorderStyle = "FixedDialog"
$inpForm.StartPosition = "CenterScreen" # moves to center of screen
$inpForm.Topmost = $true # Make it Topmost
# create a Label
$inpLbl = New-Object System.Windows.Forms.Label
$inpLbl.Width = 300
$inpLbl.Location = New-Object System.Drawing.Point(10,10)
$inpLbl.Text = "Please type in the password for user: " + $loggedInUser
# create a InputBox for the password
$inpBox = New-Object System.Windows.Forms.TextBox
$inpBox.Width = 200
$inpBox.Height = 25
$inpBox.PasswordChar = "*"
$inpBox.Text = "********"
$inpBox.Location = New-Object System.Drawing.Point(10, 35)
# create an OK Button
$inpBtn = New-Object System.Windows.Forms.Button
$inpBtn.Width = 60
$inpBtn.Height = 25
$inpBtn.Text = "OK"
$inpBtn.Location = New-Object System.Drawing.Point(250,33)
$form.AcceptButton = $inpBtn
$inpForm.Controls.AddRange(#($inpLbl, $inpBox, $inpBtn))
# OK-Button - Click event
$inpBtn.Add_Click({
$inpForm.Close()
return $inpBox.Text
})
$inpForm.ShowDialog()
}
# MAIN
$PW = InputForm (Get-WMIObject -ClassName Win32_ComputerSystem).Username
write-host $PW

Answer 1

The problem is with this last part of your function:
$inpBtn.Add_Click({
$inpForm.Close()
return $inpBox.Text
})
$inpForm.ShowDialog()
Instead of registering a custom handler for the Click event, you'll want to assign a value to the DialogResult property on the button - then inspect that result and return the value of the textbox from the function:
$inpBtn.DialogResult = 'OK'
if($inpForm.ShowDialog() -eq 'OK'){
return $inpBox.Text
}
else {
throw "User canceled password prompt!"
}