如何重构AppDelegate.m避免react-native-splash-screen致iOS端JS重复加载

I've run into this exact issue before with newer React Native versions—here's what's happening and how to fix it:

Root Cause #

The default iOS implementation of react-native-splash-screen creates a separate UIWindow to display the splash screen. In newer React Native releases, this can interfere with the main app window's lifecycle, triggering a re-mount of the React root view and thus running your JavaScript initialization code twice. This breaks logic like deep link/notification detection, since the second load won't have access to the initial launch options.

Solution 1: Modify react-native-splash-screen's Native Code #

Instead of creating a new window for the splash screen, we'll attach it directly to the app's main root view controller. Here's how:

1. Open ios/RNSplashScreen.m from the library (you can find this in your project's Pods directory if using CocoaPods).
2. Locate the + (void)show method and replace it with this:

   + (void)show {
       UIWindow *mainWindow = [UIApplication sharedApplication].keyWindow ?: [[UIApplication sharedApplication].windows firstObject];
       [self show:@"LaunchScreen" inRootView:mainWindow.rootViewController.view];
   }
   

3. Keep the rest of the library code intact. This forces the splash screen to render within your app's existing window instead of spawning a new one, eliminating the duplicate JS load.

Solution 2: Adjust AppDelegate Initialization Flow #

If you prefer not to modify the library code, you can restructure your AppDelegate.m to load React asynchronously after showing a custom splash screen:

Replace your didFinishLaunchingWithOptions method with this:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
#ifdef FB_SONARKIT_ENABLED
  InitializeFlipper(application);
#endif
  
  [GMSServices provideAPIKey:@"[redacted]"];
  
  if ([FIRApp defaultApp] == nil) {
    [FIRApp configure];
  }

  // Step 1: Set up window and show splash screen first
  self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
  UIViewController *splashVC = [UIViewController new];
  
  // Load your launch screen image (match your LaunchScreen.storyboard assets)
  UIImageView *splashImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"LaunchScreen"]];
  splashImageView.frame = self.window.bounds;
  splashImageView.contentMode = UIViewContentModeScaleAspectFill;
  [splashVC.view addSubview:splashImageView];
  
  self.window.rootViewController = splashVC;
  [self.window makeKeyAndVisible];

  // Step 2: Initialize React bridge asynchronously
  __weak typeof(self) weakSelf = self;
  self.bridge = [[RCTBridge alloc] initWithDelegate:self launchOptions:launchOptions];
  
  // Wait for bridge to load before showing React view
  dispatch_async(dispatch_get_main_queue(), ^{
    RCTRootView *rootView = [[RCTRootView alloc] initWithBridge:weakSelf.bridge moduleName:@"PartyMe" initialProperties:nil];
    rootView.backgroundColor = [[UIColor alloc] initWithRed:1.0f green:1.0f blue:1.0f alpha:1];
    
    UIViewController *reactVC = [UIViewController new];
    reactVC.view = rootView;
    
    // Switch to React view without animation
    [weakSelf.window.rootViewController presentViewController:reactVC animated:NO completion:^{
      weakSelf.window.rootViewController = reactVC;
    }];
  });

  return YES;
}

Then, in your React code, you can still use SplashScreen.hide() once your app is ready—just make sure to import the library as usual.

Verify the Fix #

After making either change, run your app and check your JavaScript logs. You should only see your initialization code execute once, and notification/deep link detection should work as expected since the launch options are preserved for the single JS load.

内容的提问来源于stack exchange，提问作者Tristan