Hello,
The IgniteUI controls are completely client-side. They don't work the same way as ASP.NET WebForms controls. So you will have to add some javascript to post to a controller. You can do this in the SelectionChanged event like this:
selectionChanged: function(evt, ui){
//get the value of the selected item
var value = ui.items[0].value;
$.post('controller/action/' + value);
}
Let me know if you have any other questions.