void ClearBindings()
{
_ignoreLeaveRow = true;
_ignorePositionChange = true;
_selectedRecord = null;
BindingSourceSupplierState.Clear();
SetReadOnly(true);
BarButtonItemDelete.Enabled = false;
BarButtonItemSave.Enabled = false;
BindingSource.DataSource = typeof(State);
_ignoreLeaveRow = false;
_ignorePositionChange = false;
}
private void RemoveRecord()
{
if (_selectedRecord.IsNew())
{
//If you clear the bindingsource for child records where the parent entity is tracked by
//the context, it will lose tracking for the child entities and cascade operations like
//delete will fail
BindingSourceSupplierState.Clear();
}
//Note that cascade delete must be set on the FK in the db in order for the related
//entities to be deleted. This is a db function, not an EF function. However in addition
//the model must know about the delete, otherwise the relationships in the context will
//get messed up. So after adding the cascade rule to the FK, the model must be updated,
//and in order to refresh a relationship the tables must be deleted and re-added
//Otherwise, we could do a delete loop
//If using DbContext instead of ObjectContext, we could do eg
//_context.SupplierRegion.RemoveRange(_selectedRecord.SupplierRegion)
BindingSource.RemoveCurrent();
}