AngularJS : 从控制器中的服务获取对象列表

Question

我有这项服务可以从 WebAPI 服务器检索汽车列表：

    angular.module('MyServices')
    .service('carService', ['$http', '$rootScope', 
        function ($http, $rootScope) {

        this.getList =function(userName, ticket)
        {
            $rootScope.$emit('My.OnBusy');

            $http.get('api/car'
               , { params: {userName: userName} }
           ).success(function (data) {
                $rootScope.$emit('My.OnIdle');

                if (data[0] && data[0].Name == "Error")
                {
                    $rootScope.$emit("My.OnError", data[0].Model);
                    return {};
                }

                return data;
           }).error(function (data, status, headers, config) {
               $rootScope.$emit('My.OnIdle');
               $rootScope.$emit("My.OnError", "Error in communication with server.");
               return {};
           });
        }
    }]
    );

在控制器中我是这样使用它的：

angular.module('MyControllers')
.controller('carController', function CarController($rootScope, $scope, $http, carService) {

    $scope.loadCars = function (userName, ticket) {
        $scope.Cars = carService.getList(userName, ticket);
    }

    $scope.loadCars($rootScope.user.email, '');
});

但是 $scope.Cars 在调用 getList 之后是未定义的。我在调用服务时尝试使用 "then" 但没有成功。

说我想在服务本身处理操作的成功和错误，我如何在控制器中得到最终结果？

Answer 1

供将来参考：

服务应该是这样的：

  angular.module('MyServices')
    .service('carService', ['$http', '$rootScope', '$q'
        function ($http, $rootScope, $q) {

        this.getList =function(userName, ticket)
        {
            $rootScope.$emit('My.OnBusy');

            var deferred = $q.defer();


            $http.get('api/car'
               , { params: {userName: userName} }
           ).success(function (data) {
                $rootScope.$emit('My.OnIdle');

                if (data[0] && data[0].Name == "Error")
                {
                    $rootScope.$emit("My.OnError", data[0].Model);
                    deferred.reject(data[0].Address);
                    //return {};
                }

                deferred.resolve(data);
                //return data;
           }).error(function (data, status, headers, config) {
               $rootScope.$emit('My.OnIdle');
               $rootScope.$emit("My.OnError", "Error in communication with server.");
               deferred.reject("Error in communication with server.");                   
               //return {};
           });

           return deferred.promise;

        }
    }]
    );

现在 "then" 在控制器中工作：

angular.module('MyControllers')
.controller('carController', function CarController($rootScope, $scope, $http, carService) {

    $scope.loadCars = function (userName, ticket) {
        carService.getList(userName, ticket).then(function (data) {
            $scope.Cars = data;
        });;
    }

    $scope.loadCars($rootScope.user.email, '');
});