validations in a form with listView

[tubin gen]

I have a form , this  has a listview  , listview contains a chekbox.Upon
form submit I want atleast one check box to be checked,
In a formvalidator I use form.get(id )  this returns formComponent and
formcomponent has a method getValue()    but in case of listView how can I
retrieve the  formComponent and its value?