how to create a dropdown multi-select combobox ?

Is it possible to allow combobox to do multi-select ?

I am using version 4.15.3 .

It seems combobox is for a single selection , is it ?

If selecting multiple items is not supported in combobox , what alternatives should I investigate ?
I am thinking perhaps a dropdown list of checkboxes ( is there any hints on how to do that ? )

Thanks in advance .

You could add the selection to an array on an OnSelectionChanged event, but this would require you to open the list, select the first item, open the list again, select your next item, and so on. Alternatively you could create a custom drop-down widget full of buttons, and set it so clicking the button toggles the selected state of it (just like a check box), and adds the selections to an array. Using a Menu Anchor widget would be your best bet here.

Or of course you could always make a custom combobox class in C++ that allows the selection of multiple items.