Install-Package Microsoft.Xaml.Behaviors.WPF
public class ListBoxBehavior : Behavior<ListBox>{private ContextMenu ctxMenu;private MenuItem saveItem;private MenuItem selectItem;public ListBoxBehavior(){}public ICommand SaveCommand{get { return (ICommand)GetValue(SaveCommandProperty); }set { SetValue(SaveCommandProperty, value); }}// Using a DependencyProperty as the backing store for SaveCommand. This enables animation, styling, binding, etc...public static readonly DependencyProperty SaveCommandProperty =DependencyProperty.Register(nameof(SaveCommand), typeof(ICommand), typeof(ListBoxBehavior),new PropertyMetadata(null));public object CmdPara{get { return (object)GetValue(CmdParaProperty); }set { SetValue(CmdParaProperty, value); }}// Using a DependencyProperty as the backing store for CmdPara. This enables animation, styling, binding, etc...public static readonly DependencyProperty CmdParaProperty =DependencyProperty.Register(nameof(CmdPara), typeof(object),typeof(ListBoxBehavior), new PropertyMetadata(""));public ICommand SelectCommand{get { return (ICommand)GetValue(SelectCommandProperty); }set { SetValue(SelectCommandProperty, value); }}// Using a DependencyProperty as the backing store for SelectCommand. This enables animation, styling, binding, etc...public static readonly DependencyProperty SelectCommandProperty =DependencyProperty.Register(nameof(SelectCommand), typeof(ICommand), typeof(ListBoxBehavior),new PropertyMetadata(null));public object SelectCmdPara{get { return (object)GetValue(SelectCmdParaProperty); }set { SetValue(SelectCmdParaProperty, value); }}// Using a DependencyProperty as the backing store for SelectCmdPara. This enables animation, styling, binding, etc...public static readonly DependencyProperty SelectCmdParaProperty =DependencyProperty.Register(nameof(SelectCmdPara), typeof(object), typeof(ListBoxBehavior),new PropertyMetadata(null));protected override void OnAttached(){CreateContextMenu();base.OnAttached();}private void CreateContextMenu(){ctxMenu = new ContextMenu();saveItem = new MenuItem();saveItem.Width = 200;saveItem.Height = 50;saveItem.Header = "Save";saveItem.FontSize = 30;saveItem.Click += SaveItem_Click;ctxMenu.Items.Add(saveItem);selectItem = new MenuItem(){Width = 200,Height = 50,Header = "Select",FontSize = 30};selectItem.Click += SelectItem_Click;ctxMenu.Items.Add(selectItem);AssociatedObject.ContextMenu = ctxMenu;}private void SelectItem_Click(object sender, RoutedEventArgs e){SelectCommand?.Execute(SelectCmdPara);}private void SaveItem_Click(object sender, RoutedEventArgs e){SaveCommand?.Execute(CmdPara);}protected override void OnDetaching(){base.OnDetaching();if (saveItem != null){saveItem.Click -= SaveItem_Click;saveItem = null;}if (ctxMenu != null){ctxMenu.Items.Clear();ctxMenu = null;}AssociatedObject.ContextMenu = null;}}<behavior:Interaction.Behaviors><local:ListBoxBehavior SaveCommand="{Binding DataContext.SaveCmd,RelativeSource={RelativeSource AncestorType=Window}}"CmdPara="{Binding Path=ItemsSource,RelativeSource={RelativeSource AncestorType=ListBox}}"SelectCommand="{Binding DataContext.SelectCmd,RelativeSource={RelativeSource AncestorType=Window}}" SelectCmdPara="{Binding Path=SelectedItem,RelativeSource={RelativeSource AncestorType=ListBox}}"/></behavior:Interaction.Behaviors>public ICommand SaveCmd { get; set; } public ICommand SelectCmd { get; set; }SaveCmd = new DelCommand(SaveCmdExecuted);SelectCmd = new DelCommand(SelectCmdExecuted);private void SelectCmdExecuted(object? obj){var bk = obj as Book;if (bk != null){MessageBox.Show($"{bk.ToString()}", $"{DateTime.Now}");}}private void SaveCmdExecuted(object? obj){var items = ((System.Collections.IList)obj).Cast<Book>()?.ToList();if (items != null && items.Any()){MessageBox.Show($"{items.Count} items", $"{DateTime.Now}");}}
<Window x:Class="WpfApp22.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:WpfApp22"xmlns:behavior="http://schemas.microsoft.com/xaml/behaviors"mc:Ignorable="d"WindowState="Maximized"Title="{Binding MainTitle}"><Window.DataContext><local:MainVM/></Window.DataContext><Grid><ListBox ItemsSource="{Binding BooksCollection}"VirtualizingPanel.IsVirtualizing="True"VirtualizingPanel.VirtualizationMode="Recycling"VirtualizingPanel.CacheLengthUnit="Item"VirtualizingPanel.CacheLength="2,2"UseLayoutRounding="True"SnapsToDevicePixels="True"ScrollViewer.CanContentScroll="True"ScrollViewer.IsDeferredScrollingEnabled="True"><ListBox.Resources><Style TargetType="ListBoxItem"><Setter Property="FontSize" Value="20"/><Style.Triggers><Trigger Property="IsMouseOver" Value="True"><Setter Property="FontSize" Value="30"/><Setter Property="Foreground" Value="Red"/></Trigger></Style.Triggers></Style></ListBox.Resources><behavior:Interaction.Behaviors><local:ListBoxBehavior SaveCommand="{Binding DataContext.SaveCmd,RelativeSource={RelativeSource AncestorType=Window}}"CmdPara="{Binding Path=ItemsSource,RelativeSource={RelativeSource AncestorType=ListBox}}"SelectCommand="{Binding DataContext.SelectCmd,RelativeSource={RelativeSource AncestorType=Window}}" SelectCmdPara="{Binding Path=SelectedItem,RelativeSource={RelativeSource AncestorType=ListBox}}"/></behavior:Interaction.Behaviors></ListBox></Grid> </Window>using Microsoft.Xaml.Behaviors; using System.Collections.ObjectModel; using System.ComponentModel; 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 WpfApp22 {/// <summary>/// Interaction logic for MainWindow.xaml/// </summary>public partial class MainWindow : Window{public MainWindow(){InitializeComponent();}}public class MainVM : INotifyPropertyChanged{public ICommand SaveCmd { get; set; }public ICommand SelectCmd { get; set; }public MainVM(){SaveCmd = new DelCommand(SaveCmdExecuted);SelectCmd = new DelCommand(SelectCmdExecuted);Task.Run(async () =>{await InitBooksCollectionAsync();});}private void SelectCmdExecuted(object? obj){var bk = obj as Book;if (bk != null){MessageBox.Show($"{bk.ToString()}", $"{DateTime.Now}");}}private void SaveCmdExecuted(object? obj){var items = ((System.Collections.IList)obj).Cast<Book>()?.ToList();if (items != null && items.Any()){MessageBox.Show($"{items.Count} items", $"{DateTime.Now}");}}private async Task InitBooksCollectionAsync(int cnt = 50000000){BooksCollection = new ObservableCollection<Book>();List<Book> bksList = new List<Book>();for (int i = 1; i < cnt + 1; i++){bksList.Add(new Book(){Id = i,Name = $"Name_{i}",ISBN = $"ISBN_{i}_{Guid.NewGuid():N}"});if (i % 1000000 == 0){await Application.Current.Dispatcher.InvokeAsync(() =>{var tempList = bksList.ToList();bksList.Clear();foreach (var bk in tempList){BooksCollection.Add(bk);}MainTitle = $"{DateTime.Now},loaded {BooksCollection.Count} items,{GetMem()}";}, System.Windows.Threading.DispatcherPriority.Background);}}}private string GetMem(){return $"memory {System.Diagnostics.Process.GetCurrentProcess().PrivateMemorySize64 / 1024 / 1024:N2} M";}private string mainTitle = $"{DateTime.Now},loading...";public string MainTitle{get{return mainTitle;}set{if (value != mainTitle){mainTitle = value;OnPropertyChanged();}}}private ObservableCollection<Book> booksCollection;public ObservableCollection<Book> BooksCollection{get{return booksCollection;}set{if (booksCollection != value){booksCollection = value;OnPropertyChanged();}}}public event PropertyChangedEventHandler? PropertyChanged;private void OnPropertyChanged([CallerMemberName] string propName = ""){var handler = PropertyChanged;handler?.Invoke(this, new PropertyChangedEventArgs(propName));}}public class DelCommand : ICommand{private Action<object?>? execute;private Predicate<object?>? canExecute;public DelCommand(Action<object?>? executeValue, Predicate<object?>? canExecuteValue = null){execute = executeValue;canExecute = canExecuteValue;}public event EventHandler? CanExecuteChanged{add{CommandManager.RequerySuggested += value;}remove{CommandManager.RequerySuggested -= value;}}public bool CanExecute(object? parameter){return canExecute == null ? true : canExecute(parameter);}public void Execute(object? parameter){execute?.Invoke(parameter);}}public class ListBoxBehavior : Behavior<ListBox>{private ContextMenu ctxMenu;private MenuItem saveItem;private MenuItem selectItem;public ListBoxBehavior(){}public ICommand SaveCommand{get { return (ICommand)GetValue(SaveCommandProperty); }set { SetValue(SaveCommandProperty, value); }}// Using a DependencyProperty as the backing store for SaveCommand. This enables animation, styling, binding, etc...public static readonly DependencyProperty SaveCommandProperty =DependencyProperty.Register(nameof(SaveCommand), typeof(ICommand), typeof(ListBoxBehavior),new PropertyMetadata(null));public object CmdPara{get { return (object)GetValue(CmdParaProperty); }set { SetValue(CmdParaProperty, value); }}// Using a DependencyProperty as the backing store for CmdPara. This enables animation, styling, binding, etc...public static readonly DependencyProperty CmdParaProperty =DependencyProperty.Register(nameof(CmdPara), typeof(object),typeof(ListBoxBehavior), new PropertyMetadata(""));public ICommand SelectCommand{get { return (ICommand)GetValue(SelectCommandProperty); }set { SetValue(SelectCommandProperty, value); }}// Using a DependencyProperty as the backing store for SelectCommand. This enables animation, styling, binding, etc...public static readonly DependencyProperty SelectCommandProperty =DependencyProperty.Register(nameof(SelectCommand), typeof(ICommand), typeof(ListBoxBehavior),new PropertyMetadata(null));public object SelectCmdPara{get { return (object)GetValue(SelectCmdParaProperty); }set { SetValue(SelectCmdParaProperty, value); }}// Using a DependencyProperty as the backing store for SelectCmdPara. This enables animation, styling, binding, etc...public static readonly DependencyProperty SelectCmdParaProperty =DependencyProperty.Register(nameof(SelectCmdPara), typeof(object), typeof(ListBoxBehavior),new PropertyMetadata(null));protected override void OnAttached(){CreateContextMenu();base.OnAttached();}private void CreateContextMenu(){ctxMenu = new ContextMenu();saveItem = new MenuItem();saveItem.Width = 200;saveItem.Height = 50;saveItem.Header = "Save";saveItem.FontSize = 30;saveItem.Click += SaveItem_Click;ctxMenu.Items.Add(saveItem);selectItem = new MenuItem(){Width = 200,Height = 50,Header = "Select",FontSize = 30};selectItem.Click += SelectItem_Click;ctxMenu.Items.Add(selectItem);AssociatedObject.ContextMenu = ctxMenu;}private void SelectItem_Click(object sender, RoutedEventArgs e){SelectCommand?.Execute(SelectCmdPara);}private void SaveItem_Click(object sender, RoutedEventArgs e){SaveCommand?.Execute(CmdPara);}protected override void OnDetaching(){base.OnDetaching();if (saveItem != null){saveItem.Click -= SaveItem_Click;saveItem = null;}if (ctxMenu != null){ctxMenu.Items.Clear();ctxMenu = null;}AssociatedObject.ContextMenu = null;}}public class Book{public int Id { get; set; }public string Name { get; set; }public string ISBN { get; set; }public override string ToString(){return $"Id:{Id},Name:{Name},ISBN:{ISBN}";}} }
