Should deleting rows in a bound DataGridView set EntityState to deleted?

Question

Hello,

I'm using EF4 in Windows Forms. My code is VB.Net. I use a BindingSource for all DataGridViews. I do not use the BindingNavigator.

I'm trying to determine something:

In a Winforms DataGridView bound to a BindingSource whose DataSource is an ObjectResult(Of T), if a row is deleted - should the underlying entity's state be set to EntityState.Deleted?

If so, couldn't I then call .SaveChanges on the context in the BindingSource.ListChanged event to delete that entity? (ListChangedType would of course be ListChangedType.ItemDeleted)

Answer 1

Hi,

ListChanged actually finishes before the delete has flowed through to Entity Framework. So you can't call SaveChanges in that event and have the data binding work.

However, the UserDeletedRow event on the data grid should be late enough for you to call SaveChanges and have it work. Just be sure to check that it isn't fired in any situations that aren't right for your the behaviour you want.

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Answer 2

Excellent information, many thanks.