import { TabView, SelectedIndexChangedEventData } from "tns-core-modules/ui/tab-view"; export function onSelectedIndexChanged(args: SelectedIndexChangedEventData) { const tabView = args.object as TabView; const newItem = tabView.items[args.newIndex]; if (newItem) { newItem.iconSource = "res://icon"; } const oldItem = tabView.items[args.oldIndex]; if (oldItem) { oldItem.iconSource = "res://testlogo"; } }