一个FileSystemWatcher和线程池的问题

说下有问题的程序，首先建立一个FileSystemWatcher，监控目录是否有新的文件到达，如果到达了就线程池分配一个线程来读取文件，然后进行后续处理，思路很简单，代码如下：

readonly FileSystemWatcher _watcher;

   2:  

string path)

   4: {           

new FileSystemWatcher

   6:                   {

   7:                       Path = path,

   8:                       Filter = Constants.Configuration.ExcelFilter,

   9:                       NotifyFilter = NotifyFilters.FileName |

  10:                                      NotifyFilters.LastWrite |

  11:                                      NotifyFilters.CreationTime

  12:                   };

  13:  

  14:     _watcher.Created += OnNewFileComesin;

true;

  16: }

  17:  

object sender, FileSystemEventArgs e)

  19: {

  20:     Task.Factory.StartNew(() =>

  21:               {   

return ReadFile(e.FullPath);

  23:               })

  24:               .ContinueWith( 

//....

  26:                );

  27: }

  28:  

string filePath)

  30: {

new StreamReader(fullPath))

  32:    {

//...

return data;

  35:    }

  36: }