Dialog - context menu, dropdown list

To show a context menu or drop-down list can be used class popupMenu. Or WPF class ContextMenu, but it can't have many items (slow, no scrollbar). To create popupMenu code can be used snippet menuSnippet.

using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

var b = new wpfBuilder("Window").WinSize(250);

b.R.Add(out Label label1, "Right-click here").Border(Brushes.Gray, 1);
label1.ContextMenuOpening += (_, e) => {
	e.Handled = true;
	var m = new popupMenu();
	m["A"] = o => { print.it(o); };
	m["B"] = o => {  };
	m.Submenu("Submenu", m => {
		m["C"] = o => {  };
		m["D"] = o => {  };
	});
	m.Separator();
	m["E"] = o => {  };
	m.Show(owner: e.Source as UIElement);
};

b.R.AddButton("Windows", o => {
	var m = new popupMenu();
	var a = wnd.getwnd.allWindows();
	foreach (var w in a) m[w.ClassName] = o => { print.it(w); };
	
	var r = o.Button.RectInScreen();
	m.Show(excludeRect: r, owner: o.Window);
});

b.R.AddButton("Files", o => {
	var m = new popupMenu();
	_Dir(m, new DirectoryInfo(@"C:\"));
	m.Show(owner: o.Window);

	static void _Dir(popupMenu m, DirectoryInfo dir) {
		foreach (var v in dir.EnumerateFileSystemInfos()) {
			if(v.Attributes.Has(FileAttributes.System|FileAttributes.Hidden)) continue;
			if(v.Attributes.Has(FileAttributes.Directory)) {
				m.Submenu(v.Name, m=> _Dir(m, v as DirectoryInfo));
			} else {
				m[v.Name]=o=>print.it(v.FullName);
			}
			m.Last.File = v.FullName;
		}
	}
});

b.R.AddOkCancel();
b.End();
if (!b.ShowDialog()) return;