Getting the old selected index in Winform's Combo box

Question

I have a combo box (winform). This combo box has some items (eg. 1,2,3,4).

Now, when I change the selection within this combo, I wish to know the old index and the new index.

How do I get this?

Possible approaches that I wish to AVOID.

1. Add an enter event, cache the current index and then on selection index change get the new index.

2. Using the selected text/selected item property received by the sender of the event.

What I ideally want:

1. In the event args that are received, I want something like:

   e.OldIndex; e.newIndex;

   Right now the event args which are received in the SelectionIndex Change event are totally useless.

2. I don't want to use more than one event.

3. If C#, does not offer this, can I have my event which passes the old index and new index as event args?

Answer 1

Seems like this is a possible duplicate

ComboBox SelectedIndexChanged event: how to get the previously selected index?

There is nothing built in, you will need to listen for this event and keep track in a class variable.

But this answer seems to suggest a sensible way of extending the combobox to keep track of the previous index https://stackoverflow.com/a/425323/81053