在一个FileSystemWatcher中监视多个路径

使用多个FileSystemWatcher会导致系统资源的浪费，因此建议在一个FileSystemWatcher中监视多个路径。可以使用WaitForChanged方法跟踪多个路径的更改。以下是代码示例：

using System.IO;

class Watcher
{
    static void Main()
    {
        FileSystemWatcher watcher = new FileSystemWatcher();
        watcher.Path = @"C:\";
        watcher.Filter = "*.*";
        watcher.IncludeSubdirectories = true;
        watcher.NotifyFilter = NotifyFilters.LastWrite | NotifyFilters.FileName;

        watcher.Changed += new FileSystemEventHandler(OnChanged);
        watcher.Created += new FileSystemEventHandler(OnChanged);
        watcher.Deleted += new FileSystemEventHandler(OnChanged);
        watcher.Renamed += new RenamedEventHandler(OnRenamed);

        watcher.EnableRaisingEvents = true;

        Console.WriteLine("Press enter to exit.");
        Console.ReadLine();
    }

    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);
    }
}