Swift3使用Firebase遇FIRAppNotConfigured异常，寻求解决办法

Hey there, let's work through this FIRAppNotConfigured error step by step—this is a super common snag when getting started with Firebase, so we'll get your app up and running in no time.

Here are the key fixes to check:

• Ensure FIRApp.configure() is called before accessing Firebase services
  The error message spells it out clearly: you need to initialize Firebase before using any of its tools (like FIRDatabase). For traditional UIKit apps, add this call in your AppDelegate's launch method:

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
      // Initialize Firebase FIRST
      FIRApp.configure()
      // Rest of your app setup code
      return true
  }
  

  If you're using SwiftUI, place the initialization in your app's root struct:

  @main
  struct YourTutorialApp: App {
      init() {
          FIRApp.configure()
      }
      
      var body: some Scene {
          WindowGroup {
              ContentView()
          }
      }
  }
  

  Double-check that this line isn't buried after code that tries to access Firebase Database—order matters here!

• Verify your GoogleService-Info.plist is properly added
  Even if you dragged the file into Xcode, it might not be linked to your target:

  1. Select the GoogleService-Info.plist file in Xcode's project navigator.
  2. Look at the right-hand sidebar (Inspector) and check the Target Membership section. Make sure your main app target is checked.
  3. Confirm the filename is exactly GoogleService-Info.plist (capitalization and spelling count!).
  4. If you're using the tutorial's final project, remember: you need to replace the included plist with your own (downloaded from your Firebase console, linked to your project). The tutorial's plist is tied to the author's Firebase project and won't work for your setup.

• Clean up build artifacts and dependencies
  Sometimes cached data causes unexpected issues:

  1. Press Command + Shift + K to clean your Xcode build folder.
  2. If you're using CocoaPods, run pod install again in your project directory to ensure all Firebase dependencies are properly installed. Double-check your Podfile includes both pod 'Firebase/Core' and pod 'Firebase/Database'.

• Double-check Keychain Sharing setup
  While this error is mostly about Firebase initialization, confirm that Keychain Sharing is enabled in your project's Signing & Capabilities tab. Make sure your team's keychain group is added (it should match the CLIENT_ID in your plist file).

If you work through these steps, you should eliminate the FIRAppNotConfigured error. Start with the first two checks—they're the most likely culprits!

内容的提问来源于stack exchange，提问作者ema so