public void RemoveTab(TabItemViewModel vm) { if (vm is VideoViewModel) { VideoTabs.Remove(vm); } else if (vm is UserViewModel) { UserTabs.Remove(vm); } else if (vm is PublicMylistViewModel) { MylistTabs.Remove(vm); } else if (vm is CommunityViewModel) { CommunityTabs.Remove(vm); } else if (vm is LiveViewModel) { LiveTabs.Remove(vm); } else if (vm is PlayListViewModel) { PlayListTabs.Remove(vm); } else { TabItems.Remove(vm); } }