使用 FileSystemWatcher 侦听文件

private ConfigureAndWatchHandler(ILoggerRepository repository, FileInfo configFile)                                    
...{                                    
    // Create a new FileSystemWatcher and set its properties.                                
    FileSystemWatcher watcher = new FileSystemWatcher();                                
                                    
    watcher.Path = m_configFile.DirectoryName;    //设定侦听文件的目录                                
    watcher.Filter = m_configFile.Name;                   //设定指定的侦听文件，不设置，则侦听整个目录                                
                                    
    // Set the notification filters 设定侦听文件的哪些属性                                
    watcher.NotifyFilter = NotifyFilters.CreationTime | NotifyFilters.LastWrite | NotifyFilters.FileName;                                
                                    
    // Add event handlers. OnChanged will do for all event handlers that fire a FileSystemEventArgs                                
    watcher.Changed += new FileSystemEventHandler(ConfigureAndWatchHandler_OnChanged);                                
    watcher.Created += new FileSystemEventHandler(ConfigureAndWatchHandler_OnChanged);                                
    watcher.Deleted += new FileSystemEventHandler(ConfigureAndWatchHandler_OnChanged);                                
    watcher.Renamed += new RenamedEventHandler(ConfigureAndWatchHandler_OnRenamed);                                
                                    
    // Begin watching. 设定是否启用侦听                                
    watcher.EnableRaisingEvents = true;                                
                                    
    //由于修改了侦听文件，会激发2次watcher的Changed事件，所以用Timer来延迟主处理                                
    // Create the timer that will be used to deliver events. Set as disabled                                
    _timer = new Timer(new TimerCallback(OnWatchedFileChange), null, Timeout.Infinite, Timeout.Infinite);                                
}                                    
                                    
private Timer _timer;                                    
private const int TimeoutMillis = 500;                                    
private void Watcher_Changed(object sender, FileSystemEventArgs e)                                    
...{                                    
    // Deliver the event in TimeoutMillis time                                
    // timer will fire only once                                
    _timer.Change(TimeoutMillis, Timeout.Infinite);                                
}                                    
private void OnWatchedFileChange(object state)                                    
...{                                    
    try                                
    ...{                                
        this._isReload = true;                            
        this._mappers = this.CetMappers();                            
    }                                
    catch ...{}                                
    finally                                
    ...{                                
        this._isReload = false;                            
    }                                
}