IO Exception: directory name is invalid using directory from File System Watcher OnChanged Event

Question

My C# application throws a System.IO.IOExcepton (The directory name is invalid) for the following code for implementing a filewatcher:

   public void OnChanged(object source, FileSystemEventArgs e)
   {
          DirectoryInfo dList = new DirectoryInfo(e.FullPath);
          FileInfo[] TxtFiles = dList.GetFiles("*.TXT");
   }

e.FullPath is "C:/Documents and Settings/Bi/Application Data/TestApp/Reports\\0MA01P62240_000005798_TRI_4947712701738551.TXT".

If you notice it seems to append a "\\" to the path when it tracks the file. Any idea what the problem may be?

Answer 1

The path C:/Documents and Settings/Bi/Application Data/TestApp/Reports\\0MA01P62240_000005798_TRI_4947712701738551.TXT isn't a directory name, it's a file name. That's why it says the directory name is invalid.

Use Path.GetDirectoryName to get the actual directory, as in:

string directoryName = Path.GetDirectoryName(e.FullPath);

It's also very strange that the FileSystemWatcher is giving you a path with forward slashes; I can't argue with what you're seeing, but those really should be backslashes. You might want to check the Path property of the FileSystemWatcher to see if that path is hard-coded.

Answer 2

Does this give the same problem?

    FileInfo fi = new FileInfo(e.FullPath);
    DirectoryInfo di = fi.Directory;
    FileInfo[] TxtFiles = di.GetFiles("*.TXT");

Answer 3

It's quite weird that the event arg e has a wrong value. Of course you can replace "\" with "/", however that's not the best way. I think you'd better tell us how you trigger the event.You know it's almost impossible that C# gives a wrong event argument unless you pass the value yourself.