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博客园 - FredGrit

WPF customize via three combied custom controls WPF DataGrid DataGridTemplateColumn DataTemplate ContentPresenter ContentTemplate WPF Customcontrol NumUpDownScroller WPF CustomControl override Template in Generic.xaml and invoke different style WPF HierarchicalDataTemplate customize via ToggleButton WPF DataGrid DataGridTemplateColumn DataTemplate call predefined DataTemplate via ContentPresenter and ContentTemplate WPF ListBox load data via contentcontrol an ItemTemplate WPF DataGrid load data from Asp.Net Core WebAPI WPF TreeView HierarchicalDataTemplate with grouped Data WPF display grouped data with GroupBox and ItemsControl WPF two listbox scroll syncchronously via behavior WPF invoke data from WebAPI,DataGridTemplate call pre defined DataTemplate via ContentPresenter WPF ListBox load data from WCF WPF datagrid load data from WCF via json, export selected items to json file WPF ItemsControl load data from WCF,DataTemplate, ContentControl WPF customize rotated wheel relentlessly via custom control WPF embed DataTemplate in HierchicalDataTemplate of TreeView WPF ContentControl, ItemsControl, ItemsPanelTemplate,VirtualizingStackPanel,convert xml string to List<T> WPF parse web.config recursively, TreeView and HierarchicalDataTemplate WPF Custom control in cs and Generic.xaml WPF ContextMenu independent visual tree resolved via Freezable implemented class WPF custom control GetTemplateChild vs FindName,NameScope separation between Logical Tree and Visual Tree, WPF ListBox ListView Datatemplate, parse xml to List via XmlSerializer and StringReader WPF TreeView HierarchicalDataTemplate, parse xml via traverse in XmlElement WPF parse xml via [XmRoot] and [XmlElement] attributes together, contentcontrol's template is ControlTemplate from Resources WPF ContentControl invoke Template from resource, reuse datatemplate WPF deserialize xml string as List via [XmlRoot] and [XmlElement] attribute WPF ContentControl Template WPF DatagridTemplate Binding DataTemplate WPF TreeView explicitly given key name to HierarchicalDataTemplate
WPF customize behavior based on Microsoft.Xaml.Behaviors....
FredGrit · 2026-04-21 · via 博客园 - FredGrit
Install-Package Microsoft.Xaml.Behaviors.WPF
public class GridBehavior : Behavior<Grid>
{
    private ContextMenu contextMenu;
    private MenuItem saveItem;
    public GridBehavior()
    {
        
    }

    private void Mi_Click(object sender, RoutedEventArgs e)
    {
        RightButtonSaveCommand?.Execute(CmdPara);
    }

    protected override void OnAttached()
    {
        CreateContextMenu();
        base.OnAttached();
        AssociatedObject.ContextMenu = contextMenu;
    }

    private void CreateContextMenu()
    {
        contextMenu = new ContextMenu();
        saveItem = new MenuItem();
        saveItem.Header = "Save";
        saveItem.Click += Mi_Click;
        contextMenu.Items.Add(saveItem);
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();
        if(saveItem!=null)
        {
            saveItem.Click -= Mi_Click;
            saveItem = null;
        }

        if(contextMenu!=null)
        {
            contextMenu.Items.Clear();
            contextMenu = null;
        }

        AssociatedObject.ContextMenu = null;
    }


    public ICommand RightButtonSaveCommand
    {
        get { return (ICommand)GetValue(RightButtonSaveCommandProperty); }
        set { SetValue(RightButtonSaveCommandProperty, value); }
    }

    // Using a DependencyProperty as the backing store for RightButtonSaveCommand.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty RightButtonSaveCommandProperty =
        DependencyProperty.Register(nameof(RightButtonSaveCommand), typeof(ICommand),
            typeof(GridBehavior), 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(GridBehavior), new PropertyMetadata(null));



}
<Window x:Class="WpfApp16.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:behavior="http://schemas.microsoft.com/xaml/behaviors"
        xmlns:local="clr-namespace:WpfApp16"
        mc:Ignorable="d"
        WindowState="Maximized"        
        Title="{Binding MainTitle}">
    <Window.DataContext>
        <local:MainVM/>
    </Window.DataContext>
    <Window.Resources>
        <local:ImgUrlConverter x:Key="ImgUrlConverter"/>
    </Window.Resources>
    <Grid>
        <ItemsControl ItemsSource="{Binding BooksCollection}">
            <ItemsControl.Template>
                <ControlTemplate>
                    <ScrollViewer CanContentScroll="True">
                        <VirtualizingStackPanel IsItemsHost="True"
                                                VirtualizingPanel.IsVirtualizing="True"
                                                VirtualizingPanel.VirtualizationMode="Recycling"
                                                VirtualizingPanel.CacheLength="3,3"
                                                VirtualizingPanel.CacheLengthUnit="Item"
                                                UseLayoutRounding="True"
                                                SnapsToDevicePixels="True"
                                                ScrollViewer.IsDeferredScrollingEnabled="True"
                                                ScrollViewer.CanContentScroll="True"/>
                    </ScrollViewer>
                </ControlTemplate>
            </ItemsControl.Template>
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Grid Width="{x:Static SystemParameters.FullPrimaryScreenWidth}"
                          Height="{x:Static SystemParameters.FullPrimaryScreenHeight}">
                        <Grid.Resources>
                            <Style TargetType="TextBlock">
                                <Setter Property="FontSize" Value="50"/>
                                <Style.Triggers>
                                    <Trigger Property="IsMouseOver" Value="True">
                                        <Setter Property="FontSize" Value="100"/>
                                        <Setter Property="Foreground" Value="Red"/>
                                    </Trigger>
                                </Style.Triggers>
                            </Style>
                        </Grid.Resources>
                        <Grid.RowDefinitions>
                            <RowDefinition/>
                            <RowDefinition/>
                        </Grid.RowDefinitions>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition/>
                            <ColumnDefinition/>
                        </Grid.ColumnDefinitions>
                        <Image Source="{Binding ImgUrl,Converter={StaticResource ImgUrlConverter}}"
                               Stretch="Uniform"
                               Grid.Row="0"
                               Grid.RowSpan="2"
                               Grid.Column="0"
                               Grid.ColumnSpan="2"/>
                        <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="1" Grid.Column="0" Grid.ColumnSpan="2"/>
                        <behavior:Interaction.Behaviors>
                            <local:GridBehavior RightButtonSaveCommand="{Binding DataContext.SaveCommand,RelativeSource={RelativeSource Mode=FindAncestor, 
                                AncestorType=Window}}"
                                                CmdPara="{Binding}" />
                        </behavior:Interaction.Behaviors>
                        <!--<behavior:Interaction.Triggers>
                            <behavior:EventTrigger EventName="MouseUp">
                                <behavior:InvokeCommandAction Command="{Binding DataContext.SaveCommand2,RelativeSource={RelativeSource AncestorType=Window}}"/>
                            </behavior:EventTrigger>
                        </behavior:Interaction.Triggers>-->
                    </Grid>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
    </Grid>
</Window>
using Microsoft.Xaml.Behaviors;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Globalization;
using System.IO;
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 WpfApp16
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }

    public class MainVM : INotifyPropertyChanged
    {
        public ICommand SaveCommand { get; set; }
        public ICommand SaveCommand2 { get; set; }
        public MainVM()
        {
            Task.Run(async () =>
            {
                await InitBooksCollectionAsync();
            });
            SaveCommand = new DelCommand(SaveCommandExecuted);
            SaveCommand2 = new DelCommand(SaveCommand2Executed);
        }

        private void SaveCommand2Executed(object? obj)
        {

        }

        private void SaveCommandExecuted(object? obj)
        {
            var bk = obj as Book;
            if (bk != null)
            {
                System.Diagnostics.Debug.WriteLine(bk.ToString());
            }
        }

        private async Task InitBooksCollectionAsync(int cnt = 100000000)
        {
            var imgDir = @"../../../Images";
            if (!Directory.Exists(imgDir))
            {
                return;
            }

            var imgs = Directory.GetFiles(imgDir);
            if (imgs == null || !imgs.Any())
            {
                return;
            }

            int imgsCount = imgs.Count();
            BooksCollection = new ObservableCollection<Book>();
            List<Book> booksList = new List<Book>();

            for (int i = 1; i < cnt + 1; i++)
            {
                booksList.Add(new Book()
                {
                    Id = i,
                    Name = $"Name_{i}",
                    //ISBN=$"ISBN_{i}_{Guid.NewGuid()}",
                    ImgUrl = $"{imgs[i % imgsCount]}"
                });

                if (i % 1000000 == 0)
                {
                    await PopulateBooksCollectionAsync(booksList);
                }
            }

            if (booksList.Any())
            {
                await PopulateBooksCollectionAsync(booksList);
            }
        }

        private async Task PopulateBooksCollectionAsync(List<Book> booksList)
        {
            var tempList = booksList.ToList();
            booksList.Clear();
            await Application.Current.Dispatcher.InvokeAsync(() =>
            {
                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 = "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 (value != booksCollection)
                {
                    booksCollection = value;
                    OnPropertyChanged();
                }
            }
        }

        public event PropertyChangedEventHandler? PropertyChanged;
        private void OnPropertyChanged([CallerMemberName] string propName = "")
        {
            var handler = PropertyChanged;
            handler?.Invoke(this, new PropertyChangedEventArgs(propName));
        }
    }

    public class GridBehavior : Behavior<Grid>
    {
        private ContextMenu contextMenu;
        private MenuItem saveItem;
        public GridBehavior()
        {
            
        }

        private void Mi_Click(object sender, RoutedEventArgs e)
        {
            RightButtonSaveCommand?.Execute(CmdPara);
        }

        protected override void OnAttached()
        {
            CreateContextMenu();
            base.OnAttached();
            AssociatedObject.ContextMenu = contextMenu;
        }

        private void CreateContextMenu()
        {
            contextMenu = new ContextMenu();
            saveItem = new MenuItem();
            saveItem.Header = "Save";
            saveItem.Click += Mi_Click;
            contextMenu.Items.Add(saveItem);
        }

        protected override void OnDetaching()
        {
            base.OnDetaching();
            if(saveItem!=null)
            {
                saveItem.Click -= Mi_Click;
                saveItem = null;
            }

            if(contextMenu!=null)
            {
                contextMenu.Items.Clear();
                contextMenu = null;
            }

            AssociatedObject.ContextMenu = null;
        }


        public ICommand RightButtonSaveCommand
        {
            get { return (ICommand)GetValue(RightButtonSaveCommandProperty); }
            set { SetValue(RightButtonSaveCommandProperty, value); }
        }

        // Using a DependencyProperty as the backing store for RightButtonSaveCommand.  This enables animation, styling, binding, etc...
        public static readonly DependencyProperty RightButtonSaveCommandProperty =
            DependencyProperty.Register(nameof(RightButtonSaveCommand), typeof(ICommand),
                typeof(GridBehavior), 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(GridBehavior), new PropertyMetadata(null));



    }


    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 ImgUrlConverter : IValueConverter
    {
        private Dictionary<string, ImageSource> imgCache = new Dictionary<string, ImageSource>();
        private static readonly object objLock = new object();
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            string imgUrl = value?.ToString();
            if (string.IsNullOrWhiteSpace(imgUrl) || !File.Exists(imgUrl))
            {
                return null;
            }

            lock (objLock)
            {
                if (imgCache.TryGetValue(imgUrl, out ImageSource img))
                {
                    return img;
                }
                using (FileStream fs = new FileStream(imgUrl, FileMode.Open, FileAccess.Read))
                {
                    BitmapImage bmi = new BitmapImage();
                    bmi.BeginInit();
                    bmi.StreamSource = fs;
                    bmi.CacheOption = BitmapCacheOption.OnLoad;
                    bmi.EndInit();
                    if (bmi.CanFreeze)
                    {
                        bmi.Freeze();
                    }
                    imgCache.TryAdd(imgUrl, bmi);
                    return bmi;
                }
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }

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

        public override string ToString()
        {
            return $"{DateTime.Now},Id:{Id},Name:{Name},ISBN:{ISBN},ImgUrl:{ImgUrl}";
        }
    }
}
2026-04-22 20:02:42,Id:40,Name:Name_40,ISBN:,ImgUrl:../../../Images\316.jpg
2026-04-22 20:02:49,Id:91,Name:Name_91,ISBN:,ImgUrl:../../../Images\370.jpg
2026-04-22 20:02:56,Id:77817208,Name:Name_77817208,ISBN:,ImgUrl:../../../Images\324.jpg

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