ios9 应用程序窗口应该有一个根视图控制器

Question

启动后我遇到了崩溃：

2015-11-13 17:47:50.744 app[18380:611105] *** 由于未捕获的异常“NSInternalInconsistencyException”而终止应用程序，原因： '应用程序窗口应该有一个根视图控制器 应用程序启动结束'

我已经阅读了有关 ios9 和根视图控制器以及现在我的 appdelegate 的其他问题：

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

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    MainViewController *main = [[MainViewController alloc] initWithNibName:@"MainViewController" bundle:nil];

    NSArray *windows = [[UIApplication sharedApplication] windows];
    for(UIWindow *window in windows) {
        NSLog(@"window: %@",window.description);
        if(window.rootViewController == nil){
            UIViewController *vc = [[UIViewController alloc]initWithNibName:nil bundle:nil];
            window.rootViewController = vc;
        }
    }

    self.window.rootViewController = main;
    [self.window setRootViewController:main];
    [self.window makeKeyAndVisible];

    return YES;
}

不幸的是，问题仍然存在。

Answer 1

也许尝试摆脱循环：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    window.backgroundColor = [UIColor whiteColor];

    MainViewController *main = [[MainViewController alloc] initWithNibName:@"MainViewController" bundle:nil];
    window.rootViewController = main;
    self.window = window;

    [window makeKeyAndVisible];
    return YES;
}