WPF ListBox load data via contentcontrol an ItemTemplate

<Window x:Class="WpfApp6.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp6"
        mc:Ignorable="d"
        Title="{Binding MainTitle}" WindowState="Maximized">
    <Window.DataContext>
        <local:MainVM/>
    </Window.DataContext>
    <Window.Resources>
        <Style TargetType="TextBlock" x:Key="TbkStyle">
            <Setter Property="FontSize" Value="30"/>
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Foreground" Value="Red"/>
                    <Setter Property="FontWeight" Value="ExtraBold"/>
                </Trigger>
            </Style.Triggers>
        </Style>

        <DataTemplate DataType="{x:Type local:Book}"
                      x:Key="BookDataTemplate">
            <Grid Margin="10">
                <Grid.Resources>
                    <Style TargetType="TextBlock"
                           BasedOn="{StaticResource TbkStyle}"/>
                </Grid.Resources>
                <Grid.RowDefinitions>
                    <RowDefinition/>
                    <RowDefinition/>
                    <RowDefinition/>
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition/>
                    <ColumnDefinition/>
                    <ColumnDefinition/>
                </Grid.ColumnDefinitions>
                <TextBlock Text="{Binding Id}" Grid.Row="0" Grid.Column="0"/>
                <TextBlock Text="{Binding Name}" Grid.Row="0" Grid.Column="1"/>
                <TextBlock Text="{Binding ISBN}" Grid.Row="0" Grid.Column="2"/>
                <TextBlock Text="{Binding Author}" Grid.Row="1" Grid.Column="0"/>
                <TextBlock Text="{Binding Comment}" Grid.Row="1" Grid.Column="1"/>
                <TextBlock Text="{Binding Content}" Grid.Row="1" Grid.Column="2"/>
                <TextBlock Text="{Binding Summary}" Grid.Row="2" Grid.Column="0"/>
                <TextBlock Text="{Binding Title}" Grid.Row="2" Grid.Column="1"/>
                <TextBlock Text="{Binding Topic}" Grid.Row="2" Grid.Column="2"/>

            </Grid>
        </DataTemplate>

        <ControlTemplate TargetType="ContentControl"
                         x:Key="ItemsControlTemplate">
            <ScrollViewer>
                <ItemsControl ItemsSource="{Binding BksCollection}"
                              ItemTemplate="{StaticResource BookDataTemplate}">
                    <ItemsControl.ItemsPanel>
                        <ItemsPanelTemplate>
                            <VirtualizingStackPanel/>
                        </ItemsPanelTemplate>
                    </ItemsControl.ItemsPanel>
                </ItemsControl>
            </ScrollViewer>
        </ControlTemplate>

        <ControlTemplate TargetType="ContentControl"
                         x:Key="LbxTemplate">
            <ListBox ItemsSource="{Binding BksCollection}"
                     ItemTemplate="{StaticResource BookDataTemplate}"
                     VirtualizingPanel.IsVirtualizing="True"
                     VirtualizingPanel.VirtualizationMode="Recycling"
                     VirtualizingPanel.CacheLength="5,5"
                     VirtualizingPanel.CacheLengthUnit="Item"
                     SnapsToDevicePixels="True"
                     UseLayoutRounding="True"
                     />
        </ControlTemplate>
    </Window.Resources>
    <Grid>
        <ContentControl Template="{StaticResource LbxTemplate}"/>
    </Grid>
</Window>



using Newtonsoft.Json;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Net.Http;
using System.Runtime.CompilerServices;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApp6
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }

    public class MainVM : INotifyPropertyChanged
    {
        static string url = "http://localhost:5000/getbooks/";
        static HttpClient client = new HttpClient()
        {
            Timeout = TimeSpan.FromHours(1)
        };

        private bool isLoading = false;

        public MainVM()
        {
            if(!DesignerProperties.GetIsInDesignMode(new DependencyObject()))
            {
                _ =

　　　　　　　　AutoLoadDataAsync();
　　　　　　　 }
　　　　　 }

 private async Task AutoLoadDataAsync(int cnt=1000000) { while(true) { await InitDataAsync(); await Task.Delay(10000); } } private async Task InitDataAsync(int cnt = 1000000) { if (isLoading) { return; } isLoading = true; MainTitle = $"{DateTime.Now},loading..."; PrintMsg(MainTitle); try { string jsonStr = await client.GetStringAsync($"{url}{cnt}"); if (!string.IsNullOrWhiteSpace(jsonStr)) { var bks = JsonConvert.DeserializeObject<List<Book>>(jsonStr); BksCollection = new ObservableCollection<Book>(bks); MainTitle = $"{DateTime.Now},FirstId:{BksCollection.FirstOrDefault()?.Id}," + $"LastId:{BksCollection.LastOrDefault()?.Id}"; PrintMsg(MainTitle); } } catch (Exception ex) { MessageBox.Show(ex?.Message); } finally { isLoading = false; } } private void PrintMsg(string msg) { #if DEBUG System.Diagnostics.Debug.WriteLine(msg); #else System.Diagnostics.Trace.WriteLine(msg); #endif } private string mainTitle = $"{DateTime.Now}"; public string MainTitle { get { return mainTitle; } set { if(value!=mainTitle) { mainTitle = value; OnPropertyChanged(); } } } private ObservableCollection<Book> bksCollection; public ObservableCollection<Book> BksCollection { get { return bksCollection; } set { if(value!=bksCollection) { bksCollection = value; OnPropertyChanged(); } } } public event PropertyChangedEventHandler? PropertyChanged; private void OnPropertyChanged([CallerMemberName]string propName="") { var handler=Volatile.Read(ref PropertyChanged); if(handler==null) { return; } handler(this, new PropertyChangedEventArgs(propName)); } } public class Book { public long Id { get; set; } public string Name { get; set; } public string ISBN { get; set; } public string Author { get; set; } public string Comment { get; set; } public string Content { get; set; } public string Summary { get; set; } public string Title { get; set; } public string Topic { get; set; } } }