WPF Progressbar in Powershell aktualisieren

#region XAML window definition
# Right-click XAML and choose WPF/Edit... to edit WPF Design
# in your favorite WPF editing tool
$xaml = @'  

<Window
   xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"  
   xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"  
   xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"  
   MinWidth="200"  
   Width ="400"  
   SizeToContent="Height"  
   Title="Backup"  
   Topmost="True" Height="250.77">  
    <Grid>
        <Label Content="Gesamtfortschritt:" HorizontalAlignment="Left" Margin="20,3,0,0" VerticalAlignment="Top"/>  
        <ProgressBar HorizontalAlignment="Left" Height="20" Margin="20,34,0,0" VerticalAlignment="Top" Width="351" Minimum="0" Maximum="100" Value="60" Name="pbStatusTotal"/>  
        <TextBlock Text="{Binding ElementName=pbStatusTotal, Path=Value, StringFormat={}{0:0}%}" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="188,36,182,168" />  

        <Label Content="Aktueller Ordner:" HorizontalAlignment="Left" Margin="20,59,0,0" VerticalAlignment="Top"/>  
        <ProgressBar HorizontalAlignment="Left" Height="20" Margin="20,90,0,0" VerticalAlignment="Top" Width="351" Minimum="0" Maximum="100" Value="60" Name="pbStatusCurrentDirectory"/>  
        <TextBlock Text="{Binding ElementName=pbStatusCurrentDirectory, Path=Value, StringFormat={}{0:0}%}" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="188,92,182,112" RenderTransformOrigin="0.31,0.521" />  

    </Grid>
</Window>

'@  
#endregion

#region Code Behind
function Convert-XAMLtoWindow
{
  param
  (
    [Parameter(Mandatory=$true)]
    [string]
    $XAML
  )
  
  Add-Type -AssemblyName PresentationFramework
  
  $reader = [XML.XMLReader]::Create([IO.StringReader]$XAML)
  $result = [Windows.Markup.XAMLReader]::Load($reader)
  $reader.Close()
  $reader = [XML.XMLReader]::Create([IO.StringReader]$XAML)
  while ($reader.Read())
  {
      $name=$reader.GetAttribute('Name')  
      if (!$name) { $name=$reader.GetAttribute('x:Name') }  
      if($name)
      {$result | Add-Member NoteProperty -Name $name -Value $result.FindName($name) -Force}
  }
  $reader.Close()
  $result
}

function Show-WPFWindow
{
  param
  (
    [Parameter(Mandatory=$true)]
    [Windows.Window]
    $Window
  )
  
  $result = $null
  $null = $window.Dispatcher.InvokeAsync{
    $result = $window.ShowDialog()
    Set-Variable -Name result -Value $result -Scope 1
  }.Wait()
  $result
}
#endregion Code Behind

#region Convert XAML to Window
$window = Convert-XAMLtoWindow -XAML $xaml 
#endregion

#region Manipulate Window Content
$pbStatusTotal = $window.FindName('pbStatusTotal')  
$pbStatusTotal.Value = $i
#endregion

$syncHash = [hashtable]::Synchronized(@{})
$syncHash.pbStatusTotal = $pbStatusTotal

$newPowershell = [powershell]::Create()

$newRunspace = [runspacefactory]::CreateRunspace()
$newRunspace.ApartmentState = "STA"  
$newRunspace.ThreadOptions = "ReuseThread"   
$newRunspace.Open()
$newRunspace.SessionStateProxy.SetVariable("syncHash",$syncHash)  

$code = { foreach ($i in (1..100))
          {
              Start-Sleep -Milliseconds 100
              Write-Host $i
              $syncHash.pbStatusTotal.Value = 50
          }
        } 

$newPowershell.AddScript({
                              # in this expample we set the progress-bar value every 500 ms
                              for ($i = 1;$i -le 10;$i++){
                                  sleep -Milliseconds 500
                                  $syncHash.pbStatusTotal.Value = $i * 10
                              }
                         })

$newPowershell.Runspace = $newRunspace
$handle = $newPowershell.BeginInvoke()

# Show Window
$result = Show-WPFWindow -Window $window