您正在尝试关闭与 Fragment 关联的 View Model 当前位于顶部 Activity

Question

我的应用在 Xamarin.Android 上运行 MvvMCross v 5+。

我正在尝试实现以下示例 https://github.com/MvvmCross/MvvmCross/tree/develop/TestProjects/Android-Support/Fragments/Example.Droid

这是我的主视图，我将在其中拥有我所有的“DrawerLayout、Toolbar、AppbarLayout、FrameLayout、NavigationView”

[Activity(Label = "View for HomeViewModel",
          LaunchMode = LaunchMode.SingleTop
          )]
    public class HomeView : MvxAppCompatActivity<HomeViewModel>, INavigationActivity
    {
    }

但是在我的 Homeview 中，我正在创建相同的整个 DrawerLayout Layout.so 每当我单击导航菜单项时，我都会像这样切换片段

switch (e.MenuItem.ItemId)
                {
                    case Resource.Id.nav_home:
                        ViewModel.ShowViewModelAndroid(typeof(OrdersViewModel));
                        //ListItemClicked(0);
                        break;
                    case Resource.Id.nav_friends:
                        ListItemClicked(1);
                        break;
                    case Resource.Id.nav_profile:
                        ListItemClicked(2);
                        break;
                }

我的片段

[MvxFragment(typeof(HomeViewModel), Resource.Id.content_frame, true)]
    [Register("Peeto.Droid.Views.Fragments.OrdersFragment")]
    public class OrdersFragment: BaseStateFragment<OrdersViewModel>
    {
    }

每当我点击 nav_home 它就会抛出以下错误

Unhandled Exception:

System.InvalidOperationException: You are trying to close ViewModel associated with Fragment when currently top Activity (Peeto.Droid.Views.HomeView does not implement IMvxFragmentHost interface!

Answer 1

您的程序包在 5.2 上时，您似乎在使用 5.0 代码。此示例仅在 5.2 上有效。您必须将您的属性更改为 [MvxFragmentPresentation] 并更新为新的演示者。

您正在尝试关闭与 Fragment 关联的 View Model 当前位于顶部 Activity

You are trying to close View Model associated with Fragment when currently top Activity

android

xamarin.android

android-fragments

mvvmcross

xamarin