How can I detect if a StorageFile was renamed or deleted in a UWP app?

Question

For a Windows Store app: how can I detect if a StorageFile was renamed or deleted outside of my application while it is open in my app?

I have a Windows 10 UWP app running on the desktop. The app lets the user open and edit documents.

Things I've tried:

• Checking DateModified:
  • I tried checking storageFile.GetBasicPropertiesAsync().DateModified, but even it I delete the file and empty the trash, the call returns successfully with the (old) DateModified. (I assume it uses an in-memory version and does not check the file on disk)
• Re-Open the StorageFile:
  • I then tried to "re-open" the file using StorageFile.GetFileFromPathAsync(file.Path). This correctly threw a FileNotFoundException the first time.
  • However, later this failed with an Unauthorized access/permission denied exception. It kind of makes sense, because I need the user to pick the file in a FileOpenPicker to have my app get permission to use it.
• Monitor the parent folder:
  • Did not get far with this one. I tried to use StorageFolder.CreateFileQuery(), but I can't access the parent folder form the StorageFile instance (again, it makes sense, because my app does not have permission to access the parent folder)

Answer 1

Found a nice and short way to check if file was deleted:

public async bool StorageFileExists(StorageFile file)
{
  try
  {
    var stream = await StorageFile.OpenReadAsync();
    stream.Dispose();
    return true;
  }
  catch (FileNotFoundException e)
  {
    return false;
  } //Other exceptions are not caught on purpose and should propagate
}

Answer 2

Even in a UWP App you can use System.IO.File.Exists(String). https://msdn.microsoft.com/de-de/library/system.io.file.exists(v=vs.110).aspx