private void Window_Loaded(object sender, RoutedEventArgs e)
{
var assm = Assembly.LoadFrom(\"wpflib.dll\");
foreach (var t in assm.GetTypes())
{
You are not instantiating the type from the DLL at all. Instead of:
var tmp = Activator.CreateInstance(typeof(UserControl)) as UserControl;
write:
var tmp = Activator.CreateInstance(t) as UserControl;
Furthermore, I would recommend that you actually write
var tmp = (UserControl) Activator.CreateInstance(t);
instead. Otherwise, if you have a bug, you will get a null-reference exception later on, which is not very informative and hard to debug. This way you get a more meaningful type-cast exception in the right place where the bug actually happens.