ArgumentException
   在 System.Collections.Hashtable.Insert(Object key, Object nvalue, Boolean add)
   在 DynamicClass.MyFileSystemWather.fsWather_Deleted(Object sender, FileSystemEventArgs e)
   在 System.IO.FileSystemWatcher.OnDeleted(FileSystemEventArgs e)
   在 System.IO.FileSystemWatcher.CompletionStatusChanged(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* overlappedPointer)
   在 System.Threading._IOCompletionCallback.PerformIOCompletionCallback(UInt32 errorCode, UInt32 numBytes, NativeOverlapped* pOVERLAP)