<ListView x:Name="listView" ItemsSource="{Binding}" ItemSelected="ListView_ItemSelected">
            <ListView.ItemTemplate>
                <DataTemplate>
                    <ViewCell>
                        <ViewCell.View>
                            <StackLayout Orientation="Horizontal">
                                <Label Text="{Binding NameBook}" FontSize="Medium" />
                            </StackLayout>
                        </ViewCell.View>
                    </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>

<ListView x:Name="listView" ItemsSource="{Binding}" ItemSelected="ListView_ItemSelected">

listView.SetBinding(ListView.ItemsSourceProperty, new Binding("."));

listView.SetBinding(ListView.ItemsSourceProperty, new Binding() {Source = this});

Label label = new Label()
        {
            FontSize = Device.GetNamedSize(NamedSize.Medium, typeof(Label))
        };

        label.SetBinding(Label.TextProperty, "NameBook");

        sl = new StackLayout()
        {

        };

        listView = new ListView()
        {
            ItemTemplate = new DataTemplate(() =>
            {
                return new ViewCell
                {
                    View = new StackLayout
                    {
                        Orientation = StackOrientation.Horizontal,
                        Children =
                        {
                            label
                        }
                    }
                };
            })
        };

        listView.SetBinding(ListView.ItemsSourceProperty, new Binding("."));
        listView.ItemSelected += ListView_ItemSelected;

        Button btn = new Button()
        {
            Text = "Добавить"
        };

        btn.Pressed += CreateFriend;

        sl.Children.Add(listView);
        sl.Children.Add(btn);
        Content = sl;