ios - didFinishLaunchingWithOptions 黑屏目标 c

Question

第一次尝试设置我的 self.window。在我的故事板中，我有一个 MainViewController 和另一个 View Controller。这是设置 self.window 的代码。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    // Override point for customization after application launch.
    // your code
    NSLog(@"applicationDidFinishLaunching");
      self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
      UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"Main" bundle: nil];
       self.window.backgroundColor = [UIColor greenColor];
       
    ViewController *mainview = [mainStoryboard instantiateViewControllerWithIdentifier:@"mainview"];
    
      self.window.rootViewController = mainview;
    
      [self.window makeKeyAndVisible];
     
    return YES;
}

我得到的只是黑屏！有什么想法吗？

标签： iosobjective-c