建立Empty Application，新建Storyboard并添加View Controller 控件后运行为空白，并报错

建立Empty Application，新建Storyboard并添加View Controller 控件后运行为空白，并报错

控制台显示：

2012-07-18 15:21:57.338 apress-8[664:f803] Application windows are expected to have a root view controller at the end of application launch

通过和Single View Application模版对比发现：需要至少修改两个地方：

1、AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
/*
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
*/
return YES;
}

2、项目配置，添加Main Storyboard