WPF populate BooksCollection via Dispatcher.InvokeAsync,DispatcherPriority.Background in mvvm

Install-Package Prism.Wpf;
Install-Package Prism.DryIOC;

　　

using System.Configuration;
using System.Data;
using System.Windows;

namespace WpfApp26
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : PrismApplication
    {
        protected override Window CreateShell()
        {
            return Container.Resolve<MainWindow>();
        }

        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
            containerRegistry.RegisterSingleton<IIDService, IDServive>();
            containerRegistry.RegisterSingleton<INameService, NameService>();
            containerRegistry.RegisterSingleton<IISBNService, ISBNService>();
            containerRegistry.RegisterSingleton<MainWindow>();
            containerRegistry.RegisterSingleton<MainWindowViewModel>();
        }
    }

    public interface IIDService
    {
        int GetId();
    }

    public class IDServive : IIDService
    {
        int idx = 0;
        public int GetId()
        {
             return Interlocked.Increment(ref idx);
        }
    }

    public interface INameService
    {
        string GetName();
    }

    public class NameService : INameService
    {
        int idx = 0;
        public string GetName()
        {
            return $"Name_{Interlocked.Increment(ref idx)}";
        }
    }

    public interface IISBNService
    {
        string GetISBN();
    }

    public class ISBNService : IISBNService
    {
        int idx = 0;
        public string GetISBN()
        {
            return $"ISBN_{Interlocked.Increment(ref idx)}_{Guid.NewGuid():N}";
        }
    }

}



 public async Task InitBooksCollectionAsync()
 {
     var imgs = Directory.GetFiles(@"../../../Images");
     if (imgs == null || !imgs.Any())
     {
         return;
     }

     int imgLen = imgs.Count();
     BooksCollection = new ObservableCollection<Book>();
     List<Book> booksList = new List<Book>();
     for (int i = 1; i < 10000001; i++)
     {
         booksList.Add(new Book()
         {
             Id = idService.GetId(),
             Name = nameService.GetName(),
             ISBN = isbnService.GetISBN(),
             Comment = $"Comment_{i}",
             Content = $"Content_{i}",
             Summary = $"Summary_{i}",
             Title = $"Title_{i}",
             Topic = $"Topic_{i}",
             ImgSource = GetImgSourceViaUrl(imgs[i % imgLen])
         });

         if (i % 100000 == 0)
         {
             await Application.Current.Dispatcher.InvokeAsync(() =>
              {
                  var tempList = booksList.ToList();
                  booksList.Clear();
                  foreach (var bk in tempList)
                  {
                      BooksCollection.Add(bk);
                  }
                  MainTitle = $"{DateTime.Now} loaded {BooksCollection.Count} items";
              }, System.Windows.Threading.DispatcherPriority.Background);
         }
     }
 }

 





using System.Configuration;
using System.Data;
using System.Windows;

namespace WpfApp26
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : PrismApplication
    {
        protected override Window CreateShell()
        {
            return Container.Resolve<MainWindow>();
        }

        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
            containerRegistry.RegisterSingleton<IIDService, IDServive>();
            containerRegistry.RegisterSingleton<INameService, NameService>();
            containerRegistry.RegisterSingleton<IISBNService, ISBNService>();
            containerRegistry.RegisterSingleton<MainWindow>();
            containerRegistry.RegisterSingleton<MainWindowViewModel>();
        }
    }

    public interface IIDService
    {
        int GetId();
    }

    public class IDServive : IIDService
    {
        int idx = 0;
        public int GetId()
        {
             return Interlocked.Increment(ref idx);
        }
    }

    public interface INameService
    {
        string GetName();
    }

    public class NameService : INameService
    {
        int idx = 0;
        public string GetName()
        {
            return $"Name_{Interlocked.Increment(ref idx)}";
        }
    }

    public interface IISBNService
    {
        string GetISBN();
    }

    public class ISBNService : IISBNService
    {
        int idx = 0;
        public string GetISBN()
        {
            return $"ISBN_{Interlocked.Increment(ref idx)}_{Guid.NewGuid():N}";
        }
    }

}
private ImageSource GetImgSourceViaUrl(string imgUrl)
 {
     if (!File.Exists(imgUrl))
     {
         return null;
     }

     if (imgCache.ContainsKey(imgUrl))
     {
         return imgCache[imgUrl];
     }

     BitmapImage bmi = new BitmapImage();
     bmi.BeginInit();
     bmi.UriSource = new Uri(imgUrl, UriKind.RelativeOrAbsolute);
     bmi.EndInit();
     if (bmi.CanFreeze)
     {
         bmi.Freeze();
     }
     imgCache[imgUrl] = bmi;
     return bmi;
 }

 

 

 

 

 

 

 

 

 

 

 

 

 

 

<prism:PrismApplication x:Class="WpfApp26.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:WpfApp26"
             xmlns:prism="http://prismlibrary.com/"> 
    
</prism:PrismApplication>


using System.Configuration;
using System.Data;
using System.Windows;

namespace WpfApp26
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : PrismApplication
    {
        protected override Window CreateShell()
        {
            return Container.Resolve<MainWindow>();
        }

        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
            containerRegistry.RegisterSingleton<IIDService, IDServive>();
            containerRegistry.RegisterSingleton<INameService, NameService>();
            containerRegistry.RegisterSingleton<IISBNService, ISBNService>();
            containerRegistry.RegisterSingleton<MainWindow>();
            containerRegistry.RegisterSingleton<MainWindowViewModel>();
        }
    }

    public interface IIDService
    {
        int GetId();
    }

    public class IDServive : IIDService
    {
        int idx = 0;
        public int GetId()
        {
             return Interlocked.Increment(ref idx);
        }
    }

    public interface INameService
    {
        string GetName();
    }

    public class NameService : INameService
    {
        int idx = 0;
        public string GetName()
        {
            return $"Name_{Interlocked.Increment(ref idx)}";
        }
    }

    public interface IISBNService
    {
        string GetISBN();
    }

    public class ISBNService : IISBNService
    {
        int idx = 0;
        public string GetISBN()
        {
            return $"ISBN_{Interlocked.Increment(ref idx)}_{Guid.NewGuid():N}";
        }
    }

}



<Window x:Class="WpfApp26.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:WpfApp26"
        xmlns:prism="http://prismlibrary.com/"
        WindowState="Maximized"
        mc:Ignorable="d"
        Title="{Binding MainTitle,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
        Height="450" Width="800"
        prism:ViewModelLocator.AutoWireViewModel="True">
    <Grid>
        <DataGrid ItemsSource="{Binding BooksCollection,Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}"
                  VirtualizingPanel.IsVirtualizing="True"
                  VirtualizingPanel.VirtualizationMode="Recycling"
                  VirtualizingPanel.CacheLength="2,2"
                  VirtualizingPanel.CacheLengthUnit="Item"
                  ScrollViewer.CanContentScroll="True"
                  ScrollViewer.IsDeferredScrollingEnabled="True"
                  CanUserAddRows="False"
                  AutoGenerateColumns="False">
            <DataGrid.Columns>
                <DataGridTemplateColumn>
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <Grid Width="{Binding DataContext.GridWidth,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Window}}"
                                  Height="{Binding DataContext.GridHeight,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=Window}}">
                                <Grid.Background>
                                    <ImageBrush ImageSource="{Binding ImgSource}"/>
                                </Grid.Background>
                                <Grid.Resources>
                                    <Style TargetType="TextBlock">
                                        <Setter Property="FontSize" Value="50"/>
                                        <Style.Triggers>
                                            <Trigger Property="IsMouseOver" Value="True">
                                                <Setter Property="Foreground" Value="Red"/>
                                            </Trigger>
                                        </Style.Triggers>
                                    </Style>
                                </Grid.Resources>
                                <Grid.RowDefinitions>
                                    <RowDefinition/>
                                    <RowDefinition/> 
                                </Grid.RowDefinitions>
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition/>
                                    <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 Comment}" Grid.Row="0" Grid.Column="3"/>
                                <TextBlock Text="{Binding Content}" Grid.Row="1" Grid.Column="0"/>
                                <TextBlock Text="{Binding Summary}" Grid.Row="1" Grid.Column="1"/>
                                <TextBlock Text="{Binding Title}" Grid.Row="1" Grid.Column="2"/>
                                <TextBlock Text="{Binding Topic}" Grid.Row="1" Grid.Column="3"/>
                            </Grid>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
            </DataGrid.Columns>
        </DataGrid>
    </Grid>
</Window>



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;
using System.IO;
using System.Collections.ObjectModel;

namespace WpfApp26
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.Loaded += async (s, e) =>
            {
                var vm = this.DataContext as MainWindowViewModel;
                if (vm != null)
                {
                    vm.GridHeight = this.ActualHeight;
                    vm.GridWidth = this.ActualWidth;
                    await vm.InitBooksCollectionAsync();
                }
            };
        }
    }

    public class MainWindowViewModel : BindableBase
    {
        IIDService idService;
        INameService nameService;
        IISBNService isbnService;
        Dictionary<string, ImageSource> imgCache = new Dictionary<string, ImageSource>();
        public MainWindowViewModel(IIDService idServiceValue, INameService nameServiceValue,
            IISBNService isbnServiceValue)
        {
            idService = idServiceValue;
            nameService = nameServiceValue;
            isbnService = isbnServiceValue;
        }

        public async Task InitBooksCollectionAsync()
        {
            var imgs = Directory.GetFiles(@"../../../Images");
            if (imgs == null || !imgs.Any())
            {
                return;
            }

            int imgLen = imgs.Count();
            BooksCollection = new ObservableCollection<Book>();
            List<Book> booksList = new List<Book>();
            for (int i = 1; i < 10000001; i++)
            {
                booksList.Add(new Book()
                {
                    Id = idService.GetId(),
                    Name = nameService.GetName(),
                    ISBN = isbnService.GetISBN(),
                    Comment = $"Comment_{i}",
                    Content = $"Content_{i}",
                    Summary = $"Summary_{i}",
                    Title = $"Title_{i}",
                    Topic = $"Topic_{i}",
                    ImgSource = GetImgSourceViaUrl(imgs[i % imgLen])
                });

                if (i % 100000 == 0)
                {
                    await Application.Current.Dispatcher.InvokeAsync(() =>
                     {
                         var tempList = booksList.ToList();
                         booksList.Clear();
                         foreach (var bk in tempList)
                         {
                             BooksCollection.Add(bk);
                         }
                         MainTitle = $"{DateTime.Now} loaded {BooksCollection.Count} items";
                     }, System.Windows.Threading.DispatcherPriority.Background);
                }
            }
        }

        private ImageSource GetImgSourceViaUrl(string imgUrl)
        {
            if (!File.Exists(imgUrl))
            {
                return null;
            }

            if (imgCache.ContainsKey(imgUrl))
            {
                return imgCache[imgUrl];
            }

            BitmapImage bmi = new BitmapImage();
            bmi.BeginInit();
            bmi.UriSource = new Uri(imgUrl, UriKind.RelativeOrAbsolute);
            bmi.EndInit();
            if (bmi.CanFreeze)
            {
                bmi.Freeze();
            }
            imgCache[imgUrl] = bmi;
            return bmi;
        }

        private ObservableCollection<Book> booksCollection;
        public ObservableCollection<Book> BooksCollection
        {
            get
            {
                return booksCollection;
            }
            set
            {
                SetProperty(ref booksCollection, value);
            }
        }

        private double gridWidth;
        public double GridWidth
        {
            get
            {
                return gridWidth;
            }
            set
            {
                SetProperty(ref gridWidth, value);
            }
        }

        private double gridHeight;
        public double GridHeight
        {
            get
            {
                return gridHeight;
            }
            set
            {
                SetProperty(ref gridHeight, value);
            }
        }

        private string mainTitle;
        public string MainTitle
        {
            get
            {
                return mainTitle;
            }
            set
            {
                SetProperty(ref mainTitle, value);
            }
        }
    }

    public class Book
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string ISBN { 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; }
        public ImageSource ImgSource { get; set; }
    }
}