public class ItemModel : INotifyPropertyChanged
    {
        #region Fields
        private string _Name;
        private string _Description;
        #endregion

        #region Events
        public event PropertyChangedEventHandler PropertyChanged;
        #endregion

        #region Public Properties
        public string Name
        {
            get
            {
                return _Name;
            }

            set
            {
                _Name = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Name)));
            }
        }

        public string Description
        {
            get
            {
                return _Description;
            }

            set
            {
                _Description = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Description)));
            }
        }
        #endregion

        #region Public Methods
        public override bool Equals(object obj)
        {
            var itemModel = obj as ItemModel;
            if (itemModel == null)
            {
                return false;
            }

            return Name.Equals(itemModel.Name);
        }
        #endregion
    }

    public class ItemModelProvider : ObservableCollection<ItemModel>
    {
        #region Events
        public event EventHandler ItemsLoaded;
        #endregion

        #region Constructor
        public ItemModelProvider()
        {
            var timer = new Timer(TimerCallback, null, 3000, 0);
        }
        #endregion

        #region Private Methods
        private void TimerCallback(object state)
        {
            Device.BeginInvokeOnMainThread(() =>
            {
                Add(new ItemModel { Name = "1", Description = "First" });
                Add(new ItemModel { Name = "2", Description = "Second" });
                Add(new ItemModel { Name = "3", Description = "Third" });
                ItemsLoaded?.Invoke(this, new EventArgs());
            });
        }
        #endregion
    }

<Grid x:Name="TheGrid">

        <Grid.Resources>
            <ResourceDictionary>
                <local:ItemModelProvider x:Key="items" />
            </ResourceDictionary>
        </Grid.Resources>

        <Grid.RowDefinitions>
            <RowDefinition />
            <RowDefinition Height="100" />
        </Grid.RowDefinitions>

        <ListView x:Name="TheListView" Margin="4" SelectedItem="{Binding ItemModel, Mode=TwoWay}" ItemsSource="{StaticResource items}" HorizontalOptions="Center" VerticalOptions="Center" BackgroundColor="#EEEEEE" >

            <ListView.ItemTemplate>
                <DataTemplate>

                    <ViewCell>

                        <Grid >

                            <Grid.RowDefinitions>
                                <RowDefinition Height="20" />
                                <RowDefinition Height="20" />
                            </Grid.RowDefinitions>

                            <Label Text="{Binding Name}" TextColor="#FF0000EE" VerticalOptions="Center"  />
                            <Label Text="{Binding Description}" Grid.Row="1"  VerticalOptions="Center" />

                        </Grid>


                    </ViewCell>

                </DataTemplate>
            </ListView.ItemTemplate>

        </ListView>

        <ActivityIndicator x:Name="TheActivityIndicator" IsRunning="True" IsVisible="True" Margin="100" />

        <StackLayout Grid.Row="1" Orientation="Horizontal">
            <Label Text="Name: " />
            <Label Text="{Binding ItemModel.Name}" />
            <Label Text="Description: " />
            <Label Text="{Binding ItemModel.Description}" />
            <Button Text="New Model" x:Name="NewModelButton" />
            <Button Text="Set To 2" x:Name="SetToTwoButton" />
        </StackLayout>

    </Grid>

public partial class AsyncListViewPage : ContentPage
{
    ItemModelProvider items;
    ItemModel two;

    private AsyncListViewModel CurrentAsyncListViewModel => BindingContext as AsyncListViewModel;

    public AsyncListViewPage()
    {
        InitializeComponent();

        CreateNewModel();

        items = (ItemModelProvider)TheGrid.Resources["items"];
        items.ItemsLoaded += Items_ItemsLoaded;

        NewModelButton.Clicked += NewModelButton_Clicked;
        SetToTwoButton.Clicked += SetToTwoButton_Clicked;
    }

    private void SetToTwoButton_Clicked(object sender, System.EventArgs e)
    {
        if (two == null)
        {
            DisplayAlert("Wait for the items to load", "Wait for the items to load", "OK");
            return;
        }

        CurrentAsyncListViewModel.ItemModel = two;
    }

    private void NewModelButton_Clicked(object sender, System.EventArgs e)
    {
        CreateNewModel();
    }

    private void CreateNewModel()
    {
        BindingContext = new AsyncListViewModel { ItemModel = new ItemModel { Name = "2", Description = "Second" } };
    }

    private void Items_ItemsLoaded(object sender, System.EventArgs e)
    {
        TheActivityIndicator.IsRunning = false;
        TheActivityIndicator.IsVisible = false;
        two = items[1];
    }
}