服务器使用OPTIONS发送200后，angular不会继续

Question

我从离子angular2服务向服务器发送一个简单的请求，如下所示：

login(authPayload) {
    let _headers = new Headers;
    _headers.append('Content-Type', 'application/json');
    return this._Http.post(this.config.url + 'login', authPayload)
      .map(res => res.json());
  }

此外，我已从我的组件订阅此登录名

 public login() {
 this.auth.login(this.registerCredentials).subscribe(allowed => {
      if (allowed) {        
        this.nav.setRoot('HomePage');
      } else {
        this.showError("Access Denied");
      }
    },
      error => {
        this.showError(error);
      });
  }

它发出OPTIONS并且我已经在我的CodeIgniter处理了这个并返回200，但是OPTIONS获得200之后的角度不会继续。它没有发布数据。我的php代码如下

 function __construct()
    {
        header('Access-Control-Allow-Origin: *');
        header("Access-Control-Allow-Headers: X-API-KEY, Origin, X-Requested-With, Content-Type, Accept, Access-Control-Request-Method");
        header("Access-Control-Allow-Methods: GET, POST, OPTIONS, PUT, DELETE");
        $method = $_SERVER['REQUEST_METHOD'];
        parent::__construct();
        if($method == "OPTIONS") {
            die();
        }
  ...................

请帮助..提前致谢