Question

I need to track current selected item in ListBox to turn off some other controls on the form when selected item become null. I try to use SelectedIndexChanged event, but it not raise when selected item is null.

Can you please advise something?

UPDATE: Selected item becomes null because i set new DataSource value with empty collection. May be it’s a reason of my problem?

I need to explain. ListBox represent collection of items from database. When user add/edit/delete some item, I refresh listbox by calling this method:

private void RefreshList()
{
     lbParts.DataSource = this.database.Fetch<part>(string.Empty);
}

It fetched all items from database, convert it to List<part> collection and set as ListBox DataSource.

Answer 1

That is incorrect. SelectedIndexChanged is raised when SelectedItem becomes null. In this case, SelectedIndex will be -1.

EDIT: you are indeed correct that when you change DataSource, you don’t get SelectedIndexChanged. I would recommend explicitly setting SelectedIndex=-1 immediately before anytime you change DataSource