我似乎无法在我的View启动时弹出警报View。代码如下。importUIKitclassStartController:UIViewController{overridefuncviewDidLoad(){super.viewDidLoad()self.view.backgroundColor=UIColor.white;startTest();}funcstartTest(){letalerta=UIAlertController(title:"InvalidTest",message:"Testingalertcontroller",preferredStyle:UIAlertC