multiselectable dropdown checkboxes using angular js

I want to design a dropdownlist of checkboxes and make the checkboxes multi-selectable. I have used the below code,but I am unable to make multiple selections as the template refreshes each time I click on a checkbox,please suggest some ideas?

{   <ul class="status-select" class="status-select" ng-if="$index == selectedFilterIndex">
     <li ng-repeat="DataValue in filter.Data.Value">
        <input type="checkbox" ng-click="OnDropDownSelectionChanged(filter,DataValue)">
                        {{DataValue.displayText}}
     </li>
     </ul> 
}