3

我正在开发一个数据库文件系统。它包括一个多目录观察器，它是一个 Windows 服务，它使用来自 .net的文件系统观察器类。

我想在单独的线程上运行每个观察程序类。线程不能在 .net 中扩展，因为它是“密封的”。我想要的是，在相关线程中运行我的观察者类的所有方法。我怎样才能做到这一点？

编辑-

以下是我的基本观察者类。

 public abstract class WatcherBase
  {
    private IWatchObject _watchObject;

    public WatcherBase() { }

    public WatcherBase(IWatchObject watchObject, bool canPauseAndContinue)
    {
        _watchObject = watchObject;
        CanPauseAndContinue = canPauseAndContinue;
    }

    public bool CanPauseAndContinue { get; set; }

    public IWatchObject ObjectToWatch
    {
        get
        { 
            return _watchObject; 
        }
    }

    public abstract void Start();
    public abstract void Pause();
    public abstract void Continue();
    public abstract void Stop();
}

以下是我从 WatcherBase 类扩展的目录观察器类

  namespace RankFs.WatcherService
  {
    public class DirectoryWatcher : WatcherBase
    {
    private WatchDirectory _directoryToWatch;
    private FileSystemWatcher _watcher;

    public DirectoryWatcher(WatchDirectory directory, bool CanPauseAndContinue)
        :base(directory ,CanPauseAndContinue)
    {
        _directoryToWatch = directory;
        _watcher = new FileSystemWatcher(_directoryToWatch.Path);
        _watcher.IncludeSubdirectories = _directoryToWatch.WatchSubDirectories;
        _watcher.Created +=new FileSystemEventHandler(Watcher_Created);
        //_watcher.Changed +=new FileSystemEventHandler(Watcher_Changed);
        _watcher.Deleted +=new FileSystemEventHandler(Watcher_Deleted);
        _watcher.Renamed +=new RenamedEventHandler(Watcher_Renamed);
    }

    public WatchDirectory DirectoryToWatch
    {
        get 
        {
            return _directoryToWatch;
        }
    }

    public override void Start()
    {
        _watcher.EnableRaisingEvents = true;
    }

    public override void Pause()
    {
        _watcher.EnableRaisingEvents = false;
    }

    public override void Continue()
    {
        _watcher.EnableRaisingEvents = true;
    }

    public override void Stop()
    {
        _watcher.EnableRaisingEvents = false;
    }

    private void Watcher_Created(object sender, FileSystemEventArgs e)
    {
       // adds a new file entry to database 
    }

    private void Watcher_Deleted(object sender, FileSystemEventArgs e)
    {
       //updates the database(deleted file)
    }

    private void Watcher_Renamed(object sender, RenamedEventArgs e)
    {
   //updates the database(renamed file)
    }
} }

我被困在这一点上。请帮助我。

4

2 回答 2

13

将FileSystemWatcher在单独的线程中触发事件。事件处理程序内部的逻辑将需要考虑这一事实并执行所需的任何同步。

如果您运行以下示例，您将看到Changed事件处理程序将在不同的线程中运行。

public static void Main(string[] args)
{
    Directory.CreateDirectory("dir1");
    Directory.CreateDirectory("dir2");
    Directory.CreateDirectory("dir3");

    Console.WriteLine("Main Thread Id: {0}", 
        Thread.CurrentThread.ManagedThreadId);

    const int watcherCount = 3;
    string[] dirs = new string[] { "dir1", "dir2", "dir3" };

    for (int i = 0; i < watcherCount; i++)
    {
        var watcher = new FileSystemWatcher();
        watcher.Path = dirs[i];
        watcher.Changed += (sender, e) =>
        {
            Console.WriteLine("File: {0} | Thread: {1}", e.Name,
                Thread.CurrentThread.ManagedThreadId);

            Thread.Sleep(2000); // Simulate long operation
        };
        watcher.EnableRaisingEvents = true;
    }

    File.WriteAllText(@"dir1\test1", "hello");
    File.WriteAllText(@"dir2\test2", "hello");
    File.WriteAllText(@"dir3\test3", "hello");

    Thread.Sleep(10000);
}

运行此示例时，我获得了以下输出：

// Main Thread Id: 1
// File: test1 | Thread: 3
// File: test2 | Thread: 4
// File: test3 | Thread: 5
// File: test1 | Thread: 3
// File: test2 | Thread: 4
// File: test3 | Thread: 5

更新： 由于您使用的是事件方法，因此FileSystemWatcher您已经在使用多线程方法，因为每个FileSystemWatcher实例的事件处理程序将以异步方式在单独的线程中触发。

于 2010-02-23T12:43:40.710 回答
0

我会编写一个包装或调整FileSystemWatcher 的新类，然后在新线程上启动我的新类。适配器类将处理来自 FSW 类的通知，然后您可以找出将这些通知广播或中继到某种编组功能的最佳方式。

有几种不同的方法可以启动新线程和数十亿个关于如何做到这一点的教程，所以我不会在这个答案中讨论这个问题。

于 2010-02-23T12:29:42.803 回答