Наследование: Android.Support.V4.App.Fragment
        private void ListItemClicked(int position)
        {
            Android.Support.V4.App.Fragment fragment = null;
            switch (position)
            {
                case 0:
                    fragment = new Fragment1();
                    break;
                case 1:
                    fragment = new Fragment2();
                    break;
                case 2:
                    fragment = new Fragment3();
                    break;
            }

            SupportFragmentManager.BeginTransaction()
                .Replace(Resource.Id.content_frame, fragment)
                .Commit();

            drawerList.SetItemChecked(position, true);
            SupportActionBar.Title = title = Sections[position];
            drawer.CloseDrawer(drawerList);
        }