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博客园 - Franky

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 implement ICommand with async execute
FredGrit · 2026-03-17 · via 博客园 - FredGrit
public class DelCommand : ICommand
{
    private Action<object?>? syncExecute;
    private readonly Func<object?, Task> asyncExecute;
    private Predicate<object?>? canExecute;
    public DelCommand(Action<object?>? executeValue, Predicate<object?>? canExecuteValue = null)
    {
        syncExecute = executeValue ?? throw new ArgumentNullException(nameof(executeValue));
        canExecute = canExecuteValue;
    }

    public DelCommand(Func<object?, Task> asyncExecuteValue, Predicate<object?>? canExecuteValue = null)
    {
        asyncExecute = asyncExecuteValue ?? throw new ArgumentNullException(nameof(asyncExecuteValue));
        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 async void Execute(object? parameter)
    {
        if (!CanExecute(parameter))
        {
            return;
        }

        if (asyncExecute != null)
        {
            await asyncExecute(parameter);
        }
        else if (syncExecute != null)
        {
            syncExecute(parameter);
        }
    }
}

private ICommand mouseDownCommand;
public ICommand MouseDownCommand
{
    get
    {
        if (mouseDownCommand == null)
        {
            mouseDownCommand = new DelCommand(MouseDownCommandExecuted);
        }
        return mouseDownCommand;
    }
}

private async Task MouseDownCommandExecuted(object? obj)
{
    var btnEventArgs = obj as MouseButtonEventArgs;
    if (btnEventArgs != null)
    {
        await InitBooksCollectionAsync();
        string msg = $"MinId:{BooksCollection.OrderBy(x => x.Id).FirstOrDefault()?.Id}\n" +
            $"MaxId:{BooksCollection.OrderByDescending(x => x.Id).FirstOrDefault()?.Id}";
        MessageBox.Show($"{msg}", 
            $"{DateTime.Now}");
    }
}

private async Task InitBooksCollectionAsync()
{
    string dataUrl = "https://localhost:7146/api/book";
    using (HttpClient client = new HttpClient())
    {
        string jsonStr = await client.GetStringAsync(dataUrl);
        if (!string.IsNullOrWhiteSpace(jsonStr))
        {
            List<Book>? bksList = JsonConvert.DeserializeObject<List<Book>>(jsonStr);
            if (bksList != null && bksList.Any())
            {
                BooksCollection = new ObservableCollection<Book>(bksList);
                MainTitle = $"{DateTime.Now},loaded last idx:{bksList.OrderByDescending(x => x.Id).FirstOrDefault()?.Id}";
            }
        }
    }
}

image

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//WebAPI
namespace WebApplication2.Models
{
    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; }
    }
}
using WebApplication2.Models;

namespace WebApplication2.Services
{
    public class BookService:IDisposable
    {
        int idx = 0;
        private int GetIdx()
        {
            return Interlocked.Increment(ref idx);
        }

        public List<Book> GetBooksList(int cnt=10000)
        {
            List<Book> booksList=new List<Book>();
            for(int i=0;i<cnt;i++)
            {
                int a=GetIdx();
                booksList.Add(new Book()
                {
                    Id = a,
                    Name = $"Name_{a}",
                    ISBN = $"ISBN_{a}_{Guid.NewGuid():N}",
                    Comment =$"Comment_{a}",
                    Content=$"Content_{a}",
                    Title=$"Title_{a}",
                    Topic=$"Topic_{a}"
                });
            }
            return booksList;
        }

        public void Dispose()
        {
            idx = 0;
        }
    }
}
using Microsoft.AspNetCore.Mvc;
using WebApplication2.Models;
using WebApplication2.Services;

namespace WebApplication2.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class BookController : Controller
    {
        private BookService bkService;
        public BookController(BookService bkServiceValue)
        {
            bkService= bkServiceValue;
        }

        [HttpGet]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public ActionResult<List<Book>> GetBooksList()
        {
            var bksList = bkService.GetBooksList();
            return Ok(bksList);
        }



    }
}

using WebApplication2.Services;

namespace WebApplication2
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);

            // Add services to the container.

            builder.Services.AddControllers();
            // Learn more about configuring OpenAPI at https://aka.ms/aspnet/openapi
            builder.Services.AddOpenApi();

            builder.Services.AddSingleton<BookService>();
            var app = builder.Build();

            // Configure the HTTP request pipeline.
            if (app.Environment.IsDevelopment())
            {
                app.MapOpenApi();
            }

            app.UseHttpsRedirection();

            app.UseAuthorization();


            app.MapControllers();

            app.Run();
        }
    }
}



//WPF
<Window x:Class="WpfApp7.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:WpfApp7"
        xmlns:behavior="http://schemas.microsoft.com/xaml/behaviors"
        mc:Ignorable="d"
        WindowState="Maximized"
        Title="{Binding MainTitle}" Height="450" Width="800">
    <behavior:Interaction.Triggers>
        <behavior:EventTrigger EventName="MouseDown">
            <behavior:InvokeCommandAction
                    Command="{Binding MouseDownCommand}"
                 PassEventArgsToCommand="True"/>
        </behavior:EventTrigger>
    </behavior:Interaction.Triggers>
    <Window.DataContext>
        <local:MainVM/>
    </Window.DataContext>
    <Grid>
        <DataGrid ItemsSource="{Binding BooksCollection}"
                  IsReadOnly="True"
                  VirtualizingPanel.IsVirtualizing="True"
                  VirtualizingPanel.VirtualizationMode="Recycling"
                  EnableRowVirtualization="True"
                  EnableColumnVirtualization="True"
                  ScrollViewer.CanContentScroll="True"
                  ScrollViewer.IsDeferredScrollingEnabled="True"
                  VirtualizingPanel.CacheLength="2,2"
                  VirtualizingPanel.CacheLengthUnit="Item"
                  AutoGenerateColumns="True"
                  CanUserAddRows="False">
            <DataGrid.Resources>
                <Style TargetType="DataGridRow">
                    <Setter Property="FontSize" Value="30"/>
                    <Style.Triggers>
                        <Trigger Property="IsMouseOver" Value="True">
                            <Setter Property="FontSize" Value="50"/>
                            <Setter Property="Foreground" Value="Red"/>
                        </Trigger>
                    </Style.Triggers>
                </Style>
            </DataGrid.Resources>
            <behavior:Interaction.Triggers>
                <behavior:EventTrigger EventName="PreviewMouseDown">
                    <behavior:InvokeCommandAction
                    Command="{Binding MouseDownCommand}"
                 PassEventArgsToCommand="True"/>
                </behavior:EventTrigger>
            </behavior:Interaction.Triggers>
        </DataGrid>
    </Grid>
</Window>

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;
using Newtonsoft.Json;

namespace WpfApp7
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
    }

    public class MainVM : INotifyPropertyChanged
    {
        public MainVM()
        {
            _=InitBooksCollectionAsync();
        }

        private ICommand mouseDownCommand;
        public ICommand MouseDownCommand
        {
            get
            {
                if (mouseDownCommand == null)
                {
                    mouseDownCommand = new DelCommand(MouseDownCommandExecuted);
                }
                return mouseDownCommand;
            }
        }

        private async Task MouseDownCommandExecuted(object? obj)
        {
            var btnEventArgs = obj as MouseButtonEventArgs;
            if (btnEventArgs != null)
            {
                await InitBooksCollectionAsync();
                string msg = $"MinId:{BooksCollection.OrderBy(x => x.Id).FirstOrDefault()?.Id}\n" +
                    $"MaxId:{BooksCollection.OrderByDescending(x => x.Id).FirstOrDefault()?.Id}";
                MessageBox.Show($"{msg}", 
                    $"{DateTime.Now}");
            }
        }

        private async Task InitBooksCollectionAsync()
        {
            string dataUrl = "https://localhost:7146/api/book";
            using (HttpClient client = new HttpClient())
            {
                string jsonStr = await client.GetStringAsync(dataUrl);
                if (!string.IsNullOrWhiteSpace(jsonStr))
                {
                    List<Book>? bksList = JsonConvert.DeserializeObject<List<Book>>(jsonStr);
                    if (bksList != null && bksList.Any())
                    {
                        BooksCollection = new ObservableCollection<Book>(bksList);
                        MainTitle = $"{DateTime.Now},loaded last idx:{bksList.OrderByDescending(x => x.Id).FirstOrDefault()?.Id}";
                    }
                }
            }
        }

        private string mainTitle="";
        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 propertyName = "")
        {
            var handler = PropertyChanged;
            if (handler != null)
            {
                handler?.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }


    public class DelCommand : ICommand
    {
        private Action<object?>? syncExecute;
        private readonly Func<object?, Task> asyncExecute;
        private Predicate<object?>? canExecute;
        public DelCommand(Action<object?>? executeValue, Predicate<object?>? canExecuteValue = null)
        {
            syncExecute = executeValue ?? throw new ArgumentNullException(nameof(executeValue));
            canExecute = canExecuteValue;
        }

        public DelCommand(Func<object?, Task> asyncExecuteValue, Predicate<object?>? canExecuteValue = null)
        {
            asyncExecute = asyncExecuteValue ?? throw new ArgumentNullException(nameof(asyncExecuteValue));
            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 async void Execute(object? parameter)
        {
            if (!CanExecute(parameter))
            {
                return;
            }

            if (asyncExecute != null)
            {
                await asyncExecute(parameter);
            }
            else if (syncExecute != null)
            {
                syncExecute(parameter);
            }
        }
    }

    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; }
    }
}

posted @ 2026-03-17 22:42  FredGrit  阅读(5)  评论()    收藏  举报