ios - Swift 通过 appdelegate 将 View 添加到前面

Question

尝试通过 AppDelegate 将 subview 添加到 UI 的前面，但它不起作用。我有一个可达性通知器，它应该在没有互联网连接时从 xib 添加 UIView。

应用委托(delegate)代码:

func reachabilityChanged(note: Notification) {
    let reachability = note.object as! Reachability
    if !reachability.isReachable {
        print("APP: Network reachable")
        if networkErrorView != nil {
            networkErrorView.removeFromSuperview()
        }
    } else {
        print("ERROR: Network not reachable")
        networkErrorView = NetworkErrorView(frame: CGRect(x: 30, y: self.window!.frame.height / 4, width: self.window!.frame.width - 60, height: self.window!.frame.height / 2))
        UIApplication.shared.keyWindow?.addSubview(networkErrorView)
        UIApplication.shared.keyWindow?.bringSubview(toFront: networkErrorView)
        print("View is showing")
    }
}

通知确实触发了，我确实在控制台上打印了“View is showing”。我试过通过 dispatchQueue.main.async 调用它，但这只会导致无限循环导致应用程序崩溃。

谢谢

Answer 1

private func dismissOfflineScreen() {
    if let navigationVC = self.window?.rootViewController?.presentedViewController as? UINavigationController, navigationVC.viewControllers.first is OfflineViewController {
        navigationVC.dismiss(animated: true, completion: nil)
    }
}

private func presentOfflineScreen() {
    let navigationVC = UINavigationController(rootViewController: OfflineViewController())
    navigationVC.view.backgroundColor = UIColor.clear
    navigationVC.modalPresentationStyle = UIModalPresentationStyle.overFullScreen
    self.window?.rootViewController?.present(navigationVC, animated: true)
}