1、ng-click操作选择器

<div class="category-tab ">
  <ul id="categoryDiv">
    <li id="rootli{{item.CategoryId}}" ng-repeat="item in rootList" ng-class="{true: 'cur',false: ''}[$index+1===1]">
      <a href="" ng-click="setRoot(item.CategoryId)">{{item.CategoryName}}</a>
    </li>
  </ul>
</div>


$scope.setRoot = function (val) {
    angular.element(document.querySelector('#categoryDiv')).find("li").removeClass('cur');
    angular.element(document.querySelector("#rootli" + val)).addClass('cur');
};