如何在MVVMCross中替换ViewModel的View？

Question

我有以下问题：我有一个ActivityListView，代码非常类似于N = 14,15等，Collect-A-Bull Mvvm Tutorials，以及它当前的ViewModel，ActivityListViewModel

观看代码：

using Android.Views;
using Android.Widget;
using Sfa.Droid.Classes;

namespace Sfa.Droid.Views.Activity
{
    [Activity(Label = "My Activity")]
    public class ActivityListView : MvxActivity
    {
        protected override void OnCreate(Bundle bundle)
        {           
            SetContentView(Resource.layout.ActivityListView);
            base.OnCreate(bundle);

            // Create your application here
        }
    }
}

ViewModel的代码：

using System.Windows.Input;


namespace Sfa.Core.ViewModels
{
    public class ActivityListViewModel : MvxViewModel
    {
        private readonly IActivityService _activityService;
        private readonly MvxSubscriptionToken _collectionChangedToken;

        private Activity _item;

        public Activity Item
        {
            get { return _item; }
            set { _item = value; RaisePropertyChanged(() => Item); }
        }

        public ActivityListViewModel(IActivityService activityService, IMvxMessenger messenger)
        {
            _activityService = activityService;
            ReloadList();
            _collectionChangedToken = messenger.Subscribe<ActivityChangedMessage>(OnActivityChanged);
        }

        private void ReloadList()
        {
            Items = _activityService.All();
        }

        private void OnActivityChanged(ActivityChangedMessage message)
        {
            ReloadList();
        }

        private List<Activity> _items;
        public List<Activity> Items
        {
            get { return _items; }
            set { _items = value; RaisePropertyChanged(() => Items); }
        }

        public ICommand ShowDetailCommand
        {
            get
            {
                return new MvxCommand<Activity>(item => ShowViewModel<ActivityDetailViewModel>(new ActivityDetailViewModel.Nav() { Id = item.Id }));
            }
        }


        private Cirrious.MvvmCross.ViewModels.MvxCommand _addCommand;
        public System.Windows.Input.ICommand AddCommand
        {
            get
            {
                _addCommand = _addCommand ?? new Cirrious.MvvmCross.ViewModels.MvxCommand(DoAdd);
                return _addCommand;
            }
        }

        private void DoAdd()
        {
            ShowViewModel<ActivityAddViewModel>();
        }
    }
}

问题出在这里：我有HomeView，我想显示MvxList（来自ActivityListView）和该布局中的Add Button，而不是ActivityListView.axml，它是如何最初的，但出于某种原因，当我点击添加按钮，它在另一个viewmodel中发送另一个表，另一个viewmodel与这个viewmodel相同，唯一的区别是它使用另一个表和其他字段。有些帮助吗？希望我的问题很明确:(我是初学者，抱歉我的经验不足。