解決集合已改變 關閉其它窗口

  ArrayList pages = new ArrayList(xtraTabbedMdiManager.Pages);
            foreach (var item in pages)
            {
                var page = item as XtraMdiTabPage;
                if ( page!= xtraTabbedMdiManager.SelectedPage)
                {
                    page.MdiChild.Close();
                }
            }

XtraMdiTabPage[] pages = new XtraMdiTabPage[xtraTabbedMdiManager.Pages.Count];
            for (int i = 0; i < pages.Length; i++)
            {
                pages[i] = xtraTabbedMdiManager.Pages[i];
            }
            for (int i = 0; i < pages.Length; i++)
            {
                if (pages[i] != xtraTabbedMdiManager.SelectedPage)
                {
                    pages[i].MdiChild.Close();
                }
            }

以上兩種方式