有两种情况:
一种是设置应用启动时默认打开的ViewController:
在appDelegate中重写didFinishLaunchingWithOptions方法:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: NSDictionary?) -> Bool {
self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
var mainVC = MainViewController(nibName: nil,bundle: nil);
var navVC = UINavigationController(rootViewController:mainVC);
self.window!.rootViewController = navVC;
self.window!.makeKeyAndVisible()
return true
}