How to tell if user has modified data using bindingsource

Question

I have a DataGridView bound to a bindingsource which is bound to a List<T>. The user clicks a row that goes to a form with textboxes etc. The textboxes are databound like so:

if (txtID.DataBindings.Count == 0)
                txtID.DataBindings.Add("Text", bindingSource, "Title");

I want to be able to detect if the user has modified any data in the controls when they click the close button so I can prompt them to say "You have un-saved work. Do you want to Save?"

I can't work out how to detect this on the binding source

Any ideas?

Thanks

UPDATE: I have worked out that I can do bindingSource.EndEdit which pushes the changes to my item in the list. In my item I can then say if Dirty throw a Messagebox but if they click "No" to saving the information the CancelEdit does not work

Answer 1

If you're bound to a DataSet then you're in luck: it has a HasChanges Property. You can get the actual changes by calling GetChanges on the dataset. This returns a new dataset containing a copy of all changed rows

Answer 2

From my updated question I found I had to store a current version of the object at BeginEdit using Memberwise.Clone and then in CancelEdit I restored that to the current.