优势

1. 异步处理：提高了文件变化处理的效率，避免了阻塞主线程。
2. 线程安全：使用了线程安全的队列来避免多线程环境下的竞态条件。
3. 日志记录：异步日志记录减少了对主线程的干扰，并且能够处理大量事件。
4. 灵活配置：可以通过配置文件调整监控目录和过滤规则，增加了灵活性。
5. 支持子目录：可以监控指定目录及其所有子目录中的文件变化。

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Threading;
using System.Threading.Tasks;// 定义一个类来封装文件变化的事件信息
public class FileChangeEvent
{public string FilePath { get; set; }public WatcherChangeTypes ChangeType { get; set; }public DateTime ChangeTime { get; set; }
}class Program
{private static FileSystemWatcher _fileSystemWatcher; // 用于监控文件系统的对象private static ConcurrentQueue<FileChangeEvent> _changeQueue = new ConcurrentQueue<FileChangeEvent>(); // 线程安全的队列，用于存储文件变化事件private static CancellationTokenSource _cts = new CancellationTokenSource(); // 用于取消异步任务的令牌源private static string _logFilePath = "file_changes.log"; // 记录日志的文件路径static async Task Main(string[] args){// 从配置文件读取监控目录和过滤规则string directoryToWatch = GetConfigValue("DirectoryToWatch", @"C:\Path\To\Directory");string filter = GetConfigValue("Filter", "*.*");// 创建FileSystemWatcher实例并配置_fileSystemWatcher = new FileSystemWatcher(directoryToWatch){NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName,Filter = filter,IncludeSubdirectories = true};// 订阅事件_fileSystemWatcher.Created += OnChanged;_fileSystemWatcher.Changed += OnChanged;_fileSystemWatcher.Deleted += OnChanged;_fileSystemWatcher.Renamed += OnRenamed;// 开始监视_fileSystemWatcher.EnableRaisingEvents = true;// 启动异步任务来处理文件变化事件Task processingTask = Task.Run(() => ProcessFileChanges(_cts.Token));Console.WriteLine($"Monitoring changes to: {directoryToWatch}");Console.WriteLine("Press 'q' to quit the sample.");// 等待用户输入以结束程序while (Console.Read() != 'q') ;// 取消处理任务并等待完成_cts.Cancel();await processingTask;}private static void OnChanged(object source, FileSystemEventArgs e){// 将文件变化事件添加到队列_changeQueue.Enqueue(new FileChangeEvent{FilePath = e.FullPath,ChangeType = e.ChangeType,ChangeTime = DateTime.Now});}private static void OnRenamed(object source, RenamedEventArgs e){// 将重命名事件添加到队列_changeQueue.Enqueue(new FileChangeEvent{FilePath = e.FullPath,ChangeType = WatcherChangeTypes.Renamed,ChangeTime = DateTime.Now});}private static async Task ProcessFileChanges(CancellationToken token){// 持续处理队列中的文件变化事件while (!token.IsCancellationRequested){if (_changeQueue.TryDequeue(out FileChangeEvent changeEvent)){// 处理并记录文件变化事件到日志await LogChangeEventAsync(changeEvent);}else{// 如果队列为空，稍作等待以减少CPU使用率await Task.Delay(100, token);}}}private static async Task LogChangeEventAsync(FileChangeEvent changeEvent){// 异步记录文件变化事件到日志文件string logMessage = $"{changeEvent.ChangeTime}: {changeEvent.FilePath} - {changeEvent.ChangeType}";await File.AppendAllTextAsync(_logFilePath, logMessage + Environment.NewLine);}private static string GetConfigValue(string key, string defaultValue){// 从配置文件或环境变量读取配置值// 这里简单地返回默认值，实际应用中可以读取真实的配置return defaultValue;}
}