let ref = FIRDatabase.database().reference()
 
override func viewDidLoad() {
    super.viewDidLoad()
    ref.observeEventType(FIRDataEventType.Value,withBlock: { (snapshot) in
        let postDict = snapshot.value as! [String : AnyObject]
        print("\(postDict)")
    })
}

跑完后我看到错误：

2016-05-19 10:04:22.264 123a[88652:13688922] The default app has not been configured yet.
2016-05-19 10:04:22.276 123a[88652:13688922] *** Terminating app due to uncaught exception 'MissingDatabaseURL',reason: 'Failed to get FIRDatabase instance: FIRApp object has no databaseURL in its FirebaSEOptions object.'
*** First throw call stack:

我阅读了文档,但无法解决此问题.
GoogleService-Info.plist我添加到项目中.