FileSystemWatcher Changed event is raised twice

Question

I have an application where I am looking for a text file and if there are any changes made to the file I am using the OnChanged eventhandler to handle the event

Answer 1

You could try to open it for write, and if successful then you could assume the other application is done with the file.

private void OnChanged(object source, FileSystemEventArgs e)
{
    try
    {
        using (var fs = File.OpenWrite(e.FullPath))
        {
        }
        //do your stuff
    }
    catch (Exception)
    {
        //no write access, other app not done
    }
}

Just opening it for write appears not to raise the changed event. So it should be safe.