not 100% sure on what you mean, but if you want to create an array of the selected items, you can access the listview's selection property (http://msdn.microsoft.com/en-us/library/windows/apps/hh872204.aspx)
i.e:
listview.selection.getItems().done( function (items) {
// items now contains an array of the selected items
// so now you can itterate over them for example, and do something with them
items.forEach(function (item) {
//do something with the item
console.log(item);
});
});