使用Typescript在AngularJS中注入工厂

(function(angular){
    "use strict";

    var app = angular.module('app',[]);
    app.factory('MyFactory',['$http',function($http) {
    ....
    });
}());

现在使用Typescript,我试图像这样使用$inject：

module Services {
    export class MyFactory {
        static $inject = ['$http'];
        constructor(private $http: ng.IHttpService) {
        }
    }
}

var app = angular.module('app',[]);

app.factory('MyFactory',Services.MyFactory) //<-- This does not work,never is instantiated.

app.factory('MyFactory',Services.MyFactory]); //<-- No deal,it has constructor dependencies

// Seems you have to do this
app.factory('MyFactory',($http) => new Services.MyFactory($http)]);

使用Typescript在Angular中注入工厂的正确方法是什么？