FileSystemWatcher 事件未在 WPF 应用程序中触发

Question

我正在尝试编写一个简单的应用程序来列出对目录的更改。我使用 microsoft 文档作为起点，我正在摸索为什么代码在我的 WPF 应用程序中无法运行，它作为控制台应用程序运行良好。

目前，这是我在 MainWindow.xaml.cs 中的内容：

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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 Syncio
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            using var watcher = new FileSystemWatcher(@"C:\Users\Connor\Desktop\Test");

            watcher.NotifyFilter = NotifyFilters.Attributes
                                 | NotifyFilters.CreationTime
                                 | NotifyFilters.DirectoryName
                                 | NotifyFilters.FileName
                                 | NotifyFilters.LastAccess
                                 | NotifyFilters.LastWrite
                                 | NotifyFilters.Security
                                 | NotifyFilters.Size;

            watcher.Changed += OnChanged;
            watcher.Created += OnCreated;
            watcher.Deleted += OnDeleted;
            watcher.Renamed += OnRenamed;
            watcher.Error += OnError;

            watcher.Filter = "*.txt";
            watcher.IncludeSubdirectories = true;
            watcher.EnableRaisingEvents = true;


        }

        private void OnChanged(object sender, FileSystemEventArgs e)
        {
            if (e.ChangeType != WatcherChangeTypes.Changed)
            {
                return;
            }
            MessageBox.Show($"Changed: {e.FullPath}");
        }

        private static void OnCreated(object sender, FileSystemEventArgs e)
        {
            string value = $"Created: {e.FullPath}";
            MessageBox.Show(value);
        }

        private void OnDeleted(object sender, FileSystemEventArgs e) =>
            Debug.WriteLine($"Deleted: {e.FullPath}");

        private void OnRenamed(object sender, RenamedEventArgs e)
        {
            MessageBox.Show($"Renamed:");
            MessageBox.Show($"    Old: {e.OldFullPath}");
            MessageBox.Show($"    New: {e.FullPath}");
        }

        private void OnError(object sender, ErrorEventArgs e) =>
            PrintException(e.GetException());

        private void PrintException(Exception? ex)
        {
            if (ex != null)
            {
                MessageBox.Show($"Message: {ex.Message}");
                MessageBox.Show("Stacktrace:");
                MessageBox.Show(ex.StackTrace);
                PrintException(ex.InnerException);
            }
        }
    }
}

我将事件显示为消息框的原因是调试语句不起作用。正如我上面所说，我可以按照本教程为微软在控制台应用程序中正常工作： https://docs.microsoft.com/en-us/dotnet/api/system.io.filesystemwatcher?view=net-6.0

但它在 WPF 中不起作用，我在这里缺少什么？没有任何事件正在触发。我开始很容易，所以我只是按文本文件过滤。

Answer 1

我已经想通了，以后有任何读者变化：

using var watcher = new FileSystemWatcher(@"path/to/file"); 

到

FileSystemWatcher watcher = new FileSystemWatcher(@"path/to/file")

奇怪，但现在可以了。