function Lock-Screen([ScriptBlock] $Payload={Start-Sleep -Seconds 5}, $Title='Busy, go away.')
{
    try
    {
      $window = New-Object Windows.Window
      $label = New-Object Windows.Controls.Label

      $label.Content = $Title
      $label.FontSize = 60
      $label.FontFamily = 'Consolas'
      $label.Background = 'Transparent'
      $label.Foreground = 'Red'
      $label.HorizontalAlignment = 'Center'
      $label.VerticalAlignment = 'Center'

      $Window.AllowsTransparency = $True
      $Window.Opacity = .7
      $window.WindowStyle = 'None'
      $window.Content = $label
      $window.Left = $window.Top = 0
      $window.WindowState = 'Maximized'
      $window.Topmost = $true

      $null = $window.Show()
      Invoke-Command -ScriptBlock $Payload
    }
    finally { $window.Close() }
}

$job =
{
  Get-ChildItem c:\windows -Recurse -ErrorAction SilentlyContinue
}

Lock-Screen -Payload $job -Title 'I am busy, go away and grab a coffee...'
复制代码