simpleXAMLWindow.ps1

#create a form (Visual c#/Windows Form/WPF App(.NET Framlework)) in VS Studio Community
#name the needed widgets (just add Name="widgetName" in the widget beacon
#copy and paste the xaml file's path in the script bellow
#finally add the logic before showing the Dialog

Add-Type -AssemblyName PresentationFramework
$xamlFile = "C:\Users\¢ombre\source\repos\testWPF01\testWPF01\MainWindow.xaml"
$inputXML = Get-Content $xamlFile -Raw
$inputXML = $inputXML -replace 'mc:Ignorable="d"', '' -replace "x:N", 'N' -replace '^<Win.*', '<Window'
[XML]$XAML = $inputXML
$reader = (New-Object System.Xml.XmlNodeReader $xaml)
try {
    $window = [Windows.Markup.XamlReader]::Load( $reader )
} catch {
    Write-Warning $_.Exception
    throw
}
$xaml.SelectNodes("//*[@Name]") | ForEach-Object {
    try {
        Set-Variable -Name "var_$($_.Name)" -Value $window.FindName($_.Name) -ErrorAction Stop
    } catch {
        throw
    }
}
#Get-Variable var_*

$var_btn.Add_Click( {
   $var_txtBox.Text = ""})

$Null = $window.ShowDialog()