WPF でポップアップに渡すべきオーナーウィンドウにできる System.Windows.Window を取得する

Utilities.GetOwnerWindow.cs

using System.Windows;
namespace Tocchann;

public static class Utilities
{
  public static Window? GetOwnerWindow()
  {
    var window = default(Window);
    foreach( Window search in Application.Current.Windows )
    {
      if( search.IsActive && search.Parent == null )
      {
        window = search;
        break;
      }
    }
    if( window == null )
    {
      window = Application.Current.MainWindow;
    }
    return window;
  }
}