HTML代碼 :<ul class="nav list-unstyled">    <li ng-repeat="d in navData" ng-class="{'hover': isHover}">        <a href="" ng-click="goUrl(d.url)">            <span ng-bind="d.name"></span>            <span ng-if="d['childlist']" ng-class="{true: 'right', false: 'down'}[!isHover]"></span>        </a>        <ul class="list-unstyled" ng-if="d['childlist']">            <li ng-repeat="cd in d.childlist">                <a href="" ng-click="goUrl(d.url)">                    <span ng-bind="cd.name"></span>                </a>            </li>        </ul>    </li></ul>js部分：    $scope.goUrl = function(url){         $scope.isHover = false;        this.isHover = !this.isHover;     };本意是點(diǎn)擊a后，所有isActive為false，然后再將點(diǎn)擊的a設(shè)置為true，但是不能實(shí)現(xiàn)，求解答。