requiredvalidator on listbox: validating whether the listbox has items or not

I think a requiredvalidator applied to a listbox validates whether the listbaox has an iemselected or not, meaning that if I have items on my listbox but none is selected then the validation fails.

Instead of that, I want to implement The following behaviour :

If the listbox contains items then I want the validation to pass but if it has no items, I want the validation to fail.

Any suggestion pls?

Thank thee :)

Hi tutus,

Maybe I'm missing something but, the number of items in a listbox is
not something the user can change (unless you have written some extra code for that).
Therefore, it's not supposed to be validated. :)

But it can be manipulated using javascript from elsewhere on the page.

Use a custom validator. The custom validator allows for both client side scripts and server side scripts. I suggest you write both.

In the client side script (javascript) you can check for

document.getElementById('the DDL ID').options.length > 0

In the server side code, you simply do an Items.Count.