C#的FileSystemWatcher如何监控文件变更？

using System; using System.IO; using System.Threading;  public class FileMonitor {     private static FileSystemWatcher _watcher;      public static void StartMonitoring(string path)     {         if (!Directory.Exists(path))         {             Console.WriteLine($"错误：指定路径 '{path}' 不存在。");             return;         }          _watcher = new FileSystemWatcher(path);          // 设置要监控的变更类型         _watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName |                                NotifyFilters.DirectoryName | NotifyFilters.Size;          // 监控子目录         _watcher.IncludeSubdirectories = true;          // 订阅事件         _watcher.Created += OnCreated;         _watcher.Changed += OnChanged;         _watcher.Deleted += OnDeleted;         _watcher.Renamed += OnRenamed;         _watcher.Error += OnError; // 监控内部错误          // 启用事件         _watcher.EnableRaisingEvents = true;          Console.WriteLine($"正在监控目录：{path} (按 'q' 键退出)");          // 保持程序运行，等待事件触发         while (Console.Read() != 'q') ;     }      private static void OnCreated(object sender, FileSystemEventArgs e)     {         Console.WriteLine($"创建: {e.FullPath}");     }      private static void OnChanged(object sender, FileSystemEventArgs e)     {         // 很多编辑器保存文件时会触发多次Changed事件，需要额外处理         Console.WriteLine($"修改: {e.FullPath}");     }      private static void OnDeleted(object sender, FileSystemEventArgs e)     {         Console.WriteLine($"删除: {e.FullPath}");     }      private static void OnRenamed(object sender, RenamedEventArgs e)     {         Console.WriteLine($"重命名: 旧名 '{e.OldFullPath}' -> 新名 '{e.FullPath}'");     }      private static void OnError(object sender, ErrorEventArgs e)     {         Console.WriteLine($"发生内部错误: {e.GetException().Message}");         // 错误通常是缓冲区溢出，可能需要增大InternalBufferSize     }      public static void Main(string[] args)     {         // 示例：监控当前应用程序运行目录         StartMonitoring(AppDomain.CurrentDomain.BaseDirectory);         // 或者指定一个具体路径，例如：StartMonitoring(@"C:TempMyMonitoredFolder");     } }

ServerShareFolder

System.Threading.Timer

Task.Delay

// 简单的去抖动示例（概念性代码，生产环境需要更健壮的实现） private static System.Collections.Concurrent.ConcurrentDictionary<string, DateTime> _lastEventTimes = new System.Collections.Concurrent.ConcurrentDictionary<string, DateTime>(); private static readonly TimeSpan DebounceDelay = TimeSpan.FromMilliseconds(500); // 500毫秒去抖  private static void OnChangedDebounced(object sender, FileSystemEventArgs e) {     // 每次事件触发，更新时间戳     _lastEventTimes[e.FullPath] = DateTime.UtcNow;      // 启动一个Task，在延迟后检查是否是最后一个事件     Task.Run(async () =>     {         await Task.Delay(DebounceDelay);         if (_lastEventTimes.TryGetValue(e.FullPath, out var lastTime) &&             (DateTime.UtcNow - lastTime) >= DebounceDelay)         {             // 确认这是在延迟期后发生的最新事件             Console.WriteLine($"【去抖动后】修改: {e.FullPath}");             _lastEventTimes.TryRemove(e.FullPath, out _); // 处理完后移除         }     }); } // 记得在FileSystemWatcher的Changed事件中调用OnChangedDebounced // _watcher.Changed += OnChangedDebounced;

_watcher.InternalBufferSize = 65536; // 增大缓冲区大小

ThreadPool

Task.Run

private static void OnChangedAsync(object sender, FileSystemEventArgs e) {     Task.Run(() =>     {         // 这里执行耗时的文件处理逻辑         Console.WriteLine($"异步处理修改: {e.FullPath}");         // 模拟耗时操作         Thread.Sleep(100);     }); } // _watcher.Changed += OnChangedAsync;

try-catch

NotifyFilters

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_watcher.NotifyFilter = NotifyFilters.FileName | NotifyFilters.LastWrite;

"*.log"

"document*.txt"

_watcher.Filter = "*.txt"; // 只监控txt文件 // 结合NotifyFilter _watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName; _watcher.IncludeSubdirectories = false; // 只监控根目录下的txt文件修改和名称变动

EnableRaisingEvents