WPF DataGrid customize behavior with multiple commands and command parameters then invoke in mvvm

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}";
        }
    }
}