Question

This is what I’m trying to do :

1. Download a file (txt, doc, xls, whatever) from a server
2. Open the file with the appropriate application using System.Diagnostics.Process.Start(path to file)
3. Monitor for file changes using a FileSystemWatcher.
4. Each time the file is changed, upload the file back to the server
5. Continue monitoring until the user has finished editing the file
6. Delete the local copy of the file
7. Exit the application

I’m stuck at step 5. How can I know whether a user has finished working on a file ?

I cannot rely on the file being locked (notepad doesn’t lock txt files for example).

I cannot rely on a process having exited or not (an example is Notepad++ for txt files : the file could be open in a tab. When you close the tab, you’ve finished editing the file, but the process is still running)

Any idea/points on how to do that in C# ?

Answer 1

You’ve excluded the two ways you could go about detecting the file being in use: file locking, and the process you start exiting.

The only alternative I an think of is to display a dialog to ask the user when they’ve finished editing.

Edit: For what it’s worth – FileZilla has this type of behaviour. You can choose to edit a file on the remote server, it downloads the file, launches the default editor, and (in the background) shows a “If you’ve finished editing – Click OK” button.
This gives me the opportunity to cancel an edit, if I’ve mucked up the file and saved it.