FileSystemWatcher如何使用

FileSystemWatcher是一个.NET类，允许开发人员监视文件系统的更改并作出相应的响应。以下是一些常见的用法示例：

监视文件夹中的文件更改：

FileSystemWatcher watcher = new FileSystemWatcher();watcher.Path = @"C:\Users\JohnDoe\Documents";watcher.Filter = "*.txt";watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName;watcher.Changed += OnChanged;watcher.Created += OnChanged;watcher.Deleted += OnChanged;watcher.Renamed += OnRenamed;watcher.EnableRaisingEvents = true;private static void OnChanged(object source, FileSystemEventArgs e){    Console.WriteLine("File: " + e.FullPath + " " + e.ChangeType);}private static void OnRenamed(object source, RenamedEventArgs e){    Console.WriteLine("File: {0} renamed to {1}", e.OldFullPath, e.FullPath);}

监视整个文件系统的更改：

FileSystemWatcher watcher = new FileSystemWatcher();watcher.Path = @"C:\";watcher.IncludeSubdirectories = true;watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName | NotifyFilters.DirectoryName;watcher.Changed += OnChanged;watcher.Created += OnChanged;watcher.Deleted += OnChanged;watcher.Renamed += OnRenamed;watcher.EnableRaisingEvents = true;

只监视特定文件的更改：

FileSystemWatcher watcher = new FileSystemWatcher();watcher.Path = @"C:\Users\JohnDoe\Documents";watcher.Filter = "importantFile.txt";watcher.NotifyFilter = NotifyFilters.LastWrite;watcher.Changed += OnChanged;watcher.EnableRaisingEvents = true;

停止监视器：

watcher.EnableRaisingEvents = false;watcher.Dispose();

需要注意的是，FileSystemWatcher可能会触发多次事件，因此需要适当处理重复事件的情况。此外，需要注意文件系统操作可能引起的性能问题和并发问题。