ios – 应用程序在使用Firebase Auth时崩溃,原因：’默认应用程序已经配置.

我正在构建我的第一个iOS应用程序,我正在使用Firebase来处理身份验证,数据库等.我添加了一个注册屏幕,并使用以下代码来创建一个新用户：

FIRAuth.auth()?.createUserWithEmail(emailAddress.text!,password: password.text!,completion: { (user,error) in

        })

当用户点击注册按钮时,有一个segue应该把他们带回原来的登录视图控制器.但是,当我运行应用程序时,它会挂起在启动屏幕上.这是调试器的输出：

2016-06-19 14:35:05.402 unitaskr[4386:82981] Configuring the default app.
2016-06-19 14:35:05.413 unitaskr[4386:] <FIRAnalytics/INFO> Firebase Analytics     v.3200000 started
2016-06-19 14:35:05.414 unitaskr[4386:] <FIRAnalytics/INFO> To enable debug logging set the following application argument: -FIRAnalyticsDebugEnabled (see ...)
2016-06-19 14:35:05.419: <FIRInstanceID/WARNING> FIRInstanceID AppDelegate proxy enabled,will swizzle app delegate remote notification handlers. To disable add "FirebaseAppDelegateProxyEnabled" to your Info.plist and set it to NO
2016-06-19 14:35:05.418 unitaskr[4386:] <FIRAnalytics/INFO> Successfully created Firebase Analytics App Delegate Proxy automatically. To disable the proxy,set the flag FirebaseAppDelegateProxyEnabled to NO in the Info.plist
2016-06-19 14:35:05.430 unitaskr[4386:82981] *** Terminating app due to uncaught exception 'com.firebase.core',reason: 'Default app has already been configured.'
*** First throw call stack:
(
0   CoreFoundation                      0x00000001100a8d85   __exceptionPreprocess + 165
1   libobjc.A.dylib                     0x00000001108e7deb objc_exception_throw + 48
2   CoreFoundation                      0x00000001100a8cbd +[NSException raise:format:] + 205
3   unitaskr                            0x000000010b58844d +[FIRApp    configureDefaultAppWithOptions:sendingNotifications:] + 102
4   unitaskr                            0x000000010b588238 +[FIRApp configure] + 302
5   unitaskr                            0x000000010b541f1a _TFC8unitaskr11AppDelegate11applicationfTCSo13UIApplication29didFinishLaunchingWithOptionsGSqGVs10DictionaryCSo8NSObjectPs9AnyObject____Sb + 266
6   unitaskr                            0x000000010b542204 _TToFC8unitaskr11AppDelegate11applicationfTCSo13UIApplication29didFinishLaunchingWithOptionsGSqGVs10DictionaryCSo8NSObjectPs9AnyObject____Sb + 180
7   UIKit                               0x000000010e5bf9ac -[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 272
8   UIKit                               0x000000010e5c0c0d -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 3415
9   UIKit                               0x000000010e5c7568 -[UIApplication _runWithMainScene:transitionContext:completion:] + 1769
10  UIKit                               0x000000010e5c4714 -[UIApplication workspaceDidEndTransaction:] + 188
11  FrontBoardServices                  0x00000001127b78c8 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 24
12  FrontBoardServices                  0x00000001127b7741 -[FBSSerialQueue _performNext] + 178
13  FrontBoardServices                  0x00000001127b7aca -[FBSSerialQueue _performNextFromRunLoopSource] + 45
14  CoreFoundation                      0x000000010ffce301 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
15  CoreFoundation                      0x000000010ffc422c __CFRunLoopDoSources0 + 556
16  CoreFoundation                      0x000000010ffc36e3 __CFRunLoopRun + 867
17  CoreFoundation                      0x000000010ffc30f8 CFRunLoopRunSpecific + 488
18  UIKit                               0x000000010e5c3f21 -[UIApplication _run] + 402
19  UIKit                               0x000000010e5c8f09 UIApplicationMain + 171
20  unitaskr                            0x000000010b542a42 main + 114
21  libdyld.dylib                       0x00000001113b692d start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

我可以根据需要提供其他信息,任何帮助/建议将不胜感激,因为我刚刚开始,并尽可能地寻求学习.祝你有美好的一天！

解决方法

我有一个消息扩展的问题：

如果您在App Extension中,您没有任何委托,您必须将FIRApp.configure()放在主ViewController的初始化文件中(或在建议的viewDidLoad中).

问题是：在消息扩展中,如果用户在打开扩展名的线程中按多个消息,init(或viewdidLoad)将被调用多次,因此由于FIRApp.configure()被调用多次而崩溃…

我发现的解决方案是在主View View中创建一个静态bool：

static var isAlreadyLaunchedOnce = false // Used to avoid 2 FIRApp configure

我在init或viewDidLoad中调用FIRApp.configure()之前测试它：

// Configure Firebase
    // ------------------
    // We check if FIRApp has already been configured with a static var,else it will crash...
    if !MessagesViewController.isAlreadyLaunchedOnce {
        FIRApp.configure()

        MessagesViewController.isAlreadyLaunchedOnce = true
    }

这样,不再有崩溃.

哦,我发现一个更优雅的方式来解决这个问题：
iOS Extension – Fatal Exception: com.firebase.core Default app has already been configured

// Configure Firebase
    // ------------------
    if FIRApp.defaultApp() == nil {
        FIRApp.configure()            
    }

这样不再是静态的)