C＃通过ThreadPool＃39; ed方法通过Observer Pattern访问GUI控件

Question

我想要同时处理几千个目录。不幸的是，我对C＃中的MultiThreading几乎没有经验。

我有：

实现观察者模式的logger类，在Service中添加LogMessage时通知我的表单。 带有listView的表单，在记录消息时收到通知，应该将消息添加到listView 我交给日志对象的服务

public partial class BrowseFolderForm : Form, ILogObserver
{    
    private IndexerService indexerService;
    private MessageLogger log;
    private static object syncLock = new object();


    public BrowseFolderForm(){
        log = new MessageLogger(this);
        indexerService = new IndexerService(log);
    }

    // Implementation of the logger classes observer callback interface
    public void NotifyChanges(Logger.Message m){
        lock (syncLock)
        {
            // add message m to the UltraListViewItem 
        }
    }

    public void startIndexing(){
       using (var finished = new CountdownEvent(1))
       {
           foreach (ObservedDirectory obsDir in dirs)
           {
              var capture = obsDir; 
              finished.AddCount();
              ThreadPool.QueueUserWorkItem(
              (state) =>
                 {
                    try
                    {
                        indexerService.StartIndexingModels(capture);
                    }
                   finally
                   {
                      //prgURLIndexing.Value = i++;
                      finished.Signal(); // Signal that the work item is complete.
                    }
                }, null);
           }
          finished.Signal(); // Signal that queueing is complete.
          finished.Wait(); // Wait for all work items to complete.
          MessageBox.Show("The task finished successfully.");
      }
   }   
}

问题是，在NotifyChanges方法中，我仍然收到一个错误，即Control无法从另一个线程访问。我该怎么办？