Avoid React Native Splash Screen Flash on iOS (the easy way)

When first opening your React Native app you may noticed a flash between the splash screen and the app starting. Historically, I've gone through a complex/confusing process that was often error prone to fix this.

Thanks to stumbling across a few lines in the docs I realized this problem is really easy to fix on iOS!

Here's the problem.

It's very subtle, especially as a gif, but you can see a brief flash. As your app gets more complex this may get more exaggerated. Fortunately, the fix is easy.

Open AppDelegate.m, find the didFinishLaunchingWithOptions method, and paste the following between [self.window makeKeyAndVisible]; and return YES;

UIView* launchScreenView = [[[NSBundle mainBundle] loadNibNamed:@"LaunchScreen" owner:self options:nil] objectAtIndex:0];
launchScreenView.frame = self.window.bounds;
rootView.loadingView = launchScreenView;

This will leave you with a didFinishLaunchingWithOptions method similar to this:

AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  RCTBridge *bridge = [[RCTBridge alloc] initWithDelegate:self launchOptions:launchOptions];
  RCTRootView *rootView = [[RCTRootView alloc] initWithBridge:bridge
                                                   moduleName:@"TicTacToeInit"
                                            initialProperties:nil];

  rootView.backgroundColor = [[UIColor alloc] initWithRed:1.0f green:1.0f blue:1.0f alpha:1];

  self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
  UIViewController *rootViewController = [UIViewController new];
  rootViewController.view = rootView;
  self.window.rootViewController = rootViewController;
  [self.window makeKeyAndVisible];
  UIView* launchScreenView = [[[NSBundle mainBundle] loadNibNamed:@"LaunchScreen" owner:self options:nil] objectAtIndex:0];
  launchScreenView.frame = self.window.bounds;
  rootView.loadingView = launchScreenView;
  return YES;
}

That's it!