基本的 FileWatcher

以下示例建立一個 FileSystemWatcher 來監視執行時指定的目錄。該元件設定為監視 LastWrite 和 LastAccess 時間的更改，建立，刪除或重新命名目錄中的文字檔案。如果更改，建立或刪除檔案，則檔案的路徑將列印到控制檯。重新命名檔案時，舊路徑和新路徑將列印到控制檯。

對於此示例，請使用 System.Diagnostics 和 System.IO 名稱空間。

FileSystemWatcher watcher;

private void watch()
{
  // Create a new FileSystemWatcher and set its properties.
  watcher = new FileSystemWatcher();
  watcher.Path = path;

 /* Watch for changes in LastAccess and LastWrite times, and
       the renaming of files or directories. */
  watcher.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite
                         | NotifyFilters.FileName | NotifyFilters.DirectoryName;

  // Only watch text files.      
  watcher.Filter = "*.txt*";

  // Add event handler.
  watcher.Changed += new FileSystemEventHandler(OnChanged);
  // Begin watching.      
  watcher.EnableRaisingEvents = true;
}

// Define the event handler.
private void OnChanged(object source, FileSystemEventArgs e)
{
  //Copies file to another directory or another action.
  Console.WriteLine("File: " +  e.FullPath + " " + e.ChangeType);
}