AngularJS如何使用promise和defer

I have this service:

我有这项服务:

angular.module('taskModule').service('myService', ['$modal', '$q', myService]);

function myService($modal, $q) {
  this.displayModal = function(data) {
    return $q(function(resolve, reject) {
      $modal.open({
        templateUrl: 'taskModule/taskModule/modal.tpl.html',
        controller: function() {
          this.datas = data;
          this.buttonAction = function(id) {
            console.log(id);
          };
        },
        controllerAs: 'myCtrl'
      });
    });
  };
}
angular.module