Simple PowershelL scope problem is VS2012

Question

SIMPLISTIC example with an added feature:

$Updated = "NO"

#region iS THE SYSTEM UPDATED?
Add-Type -Assembly PresentationFramework
[xml]$xaml = @"
<Window 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Name="Window" Title="Initial Window" WindowStartupLocation = "CenterScreen"
    SizeToContent = "WidthAndHeight" ShowInTaskbar = "True" Background = "lightgray"> 
    <StackPanel x:Name='StackPanel'> 
        <TextBox     x:Name='textbox' Text='Has the machine been completely Updated?' IsReadOnly="True" />      
        <RadioButton x:Name="Item1" Content = 'YES' Foreground='Green'/>
        <RadioButton x:Name="Item2" Content = 'NO'  Foreground='RED'/>
    </StackPanel>
</Window>
"@

$reader=(New-Object System.Xml.XmlNodeReader $xaml)
$Window=[Windows.Markup.XamlReader]::Load( $reader )

$zzz = $xaml.SelectNodes("//*[@*[contains(translate(name(.),'n','N'),'Name')]]") 

ForEach ($z in $zzz) 
{
    Set-Variable -Name ($z.Name) -Value $Window.FindName($z.Name)
}
[System.Windows.RoutedEventHandler]$Script:CheckedEventHandler = 
{
    Write-Host "changed"
    if ( $_.source.Content.Equals( "YES" ) )
    {
       $Updated = "YES"
    }
    else
    {
       $Updated = "NO"
    }
    Write-Host $Updated
}
$StackPanel.AddHandler([System.Windows.Controls.RadioButton]::CheckedEvent, $CheckedEventHandler)

$Window.Showdialog() | Out-Null
Write-Host $Updated

if ( $Updated.Equals("NO") )
{
   Write-Host "Exiting"
   Exit
}

Write-Host "Carry On"

Extracted from textbook examples

What is added <$Updated>

Within the scope of the dialog box, the value is toggled by the use of the radio buttons and displayed by a <Write-Host> diagnostic.

But when the dialog box exits, the <$Updated> value reverts to the original i.e. unchanged value.

I presume the dialog box creates a local or scope version of the variable different from the global variable.

So how do I get the dialog box to reference the Global Variable? Or return the local version as a string, but I would prefer the former approach.

Answer 1

If you're using VS Code (I can't speak for Visual Studio because I rarely use it) and set a breakpoint on line 33 of your script ($Updated = "YES") and whan you examine "Variables" pane, you'll find there are two $Updated variables. One with a Script scope and the other with a Global scope.

Use an explicit scope when declaring and referencing that variable:

$Script:Updated = "NO"

#region iS THE SYSTEM UPDATED?
Add-Type -Assembly PresentationFramework
[xml]$xaml = @"
<Window 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    x:Name="Window" Title="Initial Window" WindowStartupLocation = "CenterScreen"
    SizeToContent = "WidthAndHeight" ShowInTaskbar = "True" Background = "lightgray"> 
    <StackPanel x:Name='StackPanel'> 
        <TextBox     x:Name='textbox' Text='Has the machine been completely Updated?' IsReadOnly="True" />      
        <RadioButton x:Name="Item1" Content = 'YES' Foreground='Green'/>
        <RadioButton x:Name="Item2" Content = 'NO'  Foreground='RED'/>
    </StackPanel>
</Window>
"@

$reader=(New-Object System.Xml.XmlNodeReader $xaml)
$Window=[Windows.Markup.XamlReader]::Load( $reader )

$zzz = $xaml.SelectNodes("//*[@*[contains(translate(name(.),'n','N'),'Name')]]") 

ForEach ($z in $zzz) 
{
    Set-Variable -Name ($z.Name) -Value $Window.FindName($z.Name)
}
[System.Windows.RoutedEventHandler]$Script:CheckedEventHandler = 
{
    Write-Host "changed"
    if ( $_.source.Content.Equals( "YES" ) )
    {
       $Script:Updated = "YES"
    }
    else
    {
       $Script:Updated = "NO"
    }
    Write-Host $Script:Updated
}
$StackPanel.AddHandler([System.Windows.Controls.RadioButton]::CheckedEvent, $CheckedEventHandler)

$Window.Showdialog() | Out-Null
Write-Host $Script:Updated

if ( $Script:Updated.Equals("NO") )
{
   Write-Host "Exiting"
   Exit
}

Write-Host "Carry On"