Swift中的FBGraphUser

Question

我在Swift中使用Facebook iOS SDK访问Facebook，我希望使用FBGraphUser（或FBGraphPlace，FBGraphLocation）协议，而不是使用纯Dictionary。请求成功完成，但我无法将结果转换为FBProtocol

FBRequestConnection.startForMeWithCompletionHandler { (connection: FBRequestConnection!, result: AnyObject!, error: NSError!) -> Void in
     // this does not work
    if let fbGraphUser = result as? FBGraphUser {
        NSLog("\(fbGraphUser)")
    }

     // this works
    if let fbGraphUserDict = result as? Dictionary<String, AnyObject>{
        println("\(fbGraphUserDict)")
    }
}

我应该如何打开选项以获取FBxxxx对象？

欢呼声