我希望在标签条应用程序中的启动时打开一个特定的选项卡,我得到警告Warning: Attempt to present <settingsViewController: 0x16e49870> on <UITabBarController: 0x16d25440> whose view is not in the window hierarchy!。self.tabBarController.selectedIndex = 1;
我试过在DidFinishLaun
我试图在ViewWillAppear上创建一个UIAlertController,它给了我以下警告。"Warning: Attempt to present <UIAlertController: 0x7f8798c15df0> on <ViewController: 0x7f8798f81450>据我所知,它已经准备好在ViewWillAppear中向用户显示视图了,但相当昂贵。但是,当我将相同的UIAler