iOS 13以后苹果增加了SceneDelegate来管理窗口。iOS 13以前自定义个Window进行显示，下面两种方式都可以
- 方式一：
let newWindow = UIWindow() newWindow.frame = CGRect.init(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height) newWindow.backgroundColor = UIColor.red newWindow.isHidden = false
- 方式二：
let newWindow = UIWindow() newWindow.frame = CGRect.init(x: 0, y: 0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height) newWindow.backgroundColor = UIColor.red newWindow.windowLevel = UIWindow.Level.alert newWindow.makeKeyAndVisible()
iOS 13以后新建或自定义的Window必须注册到SceneDelegate中
swift
if #available(iOS 13.0, *) { // 通知注册方式看场景进行添加，不需要可以去除 NotificationCenter.default.addObserver(forName: UIScene.willConnectNotification, object: nil, queue: nil) { (note) in newWindow.windowScene = note.object as? UIWindowScene } // 主要注册 for windowScene in UIApplication.shared.connectedScenes { if (windowScene.activationState == UIScene.ActivationState.foregroundActive) { newWindow.windowScene = windowScene as? UIWindowScene } } }
OC注册
if (@available(iOS 13.0, *)) { // 通知注册方式看场景进行添加，这里我就不写了 // 主要注册 for (UIWindowScene *windowScene in [UIApplication sharedApplication].connectedScenes) { if (windowScene.activationState == UISceneActivationStateForegroundActive) { newWindow.windowScene = windowScene; break; } } }
- 在有些方法中注册时
[UIApplication sharedApplication].connectedScenes为空，可以延时进行注册，比如didFinishLaunchingWithOptions方法执行时会为空。
