http://stackoverflow.com/questions/14974271/can-you-change-a-path-without-reloading-the-controller-in-angularjs
$location.search({vln: $scope.vln_id}, false);
会改变url中 ? 后面的 搜索参数,但是controller不会重新实例化。
angular 官方文档:https://docs.angularjs.org/guide/$location