Entity framework -Undo changes takes a very long time

[desanti]

Hello ! I'm using vb.net 2017 with EF 6 and Sql server 2008R2. On my form I have a bindingsource bound to entity.also I have a datagridview that has Mybindingsource as datasource. I have a save button and a Undo button.So the user make changes and can press the save button to save the data on database and Undo button to undo the changes. For the Undo button I have this code :

For it = MyBindingSource.Count - 1 To 0 Step -1
Dim entry As Infrastructure.DbEntityEntry = context.Entry(MyBindingSource.Item(it))
Select Case entry.State
Case 1
entry.State = EntityState.Detached
MyBindingSource.Remove(MyBindingSource.Item(it))
Case EntityState.Modified
entry.CurrentValues.SetValues(entry.OriginalValues)
entry.State = EntityState.Unchanged
Case EntityState.Deleted
entry.State = EntityState.Modified
entry.CurrentValues.SetValues(entry.OriginalValues)
entry.State = EntityState.Unchanged
End Select
Next

this code is working correctly , but I have noticed that when Mybindingsource has large data , for example 2300 that i'm testing now , this code needs 2-3 minutes to be executed. What can I do ? Thank you !