如何快速关闭消息应用程序？

Question

你能在这里看到吗：https://vimeo.com/279403383

我正在尝试显示密码视图。因为这个应用程序对安全性很敏感。

所以如果应用确实进入了后台，请请求密码。

在这种情况下工作得很好。

但是，具体的情况很奇怪。

func applicationDidEnterBackground(_ application: UIApplication) {
            guard let passcodeManageView = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "passcodeManageView") as? PasscodeManageViewController else { return }
            passcodeManageView.state = State.loginMode
            passcodeManageView.modalPresentationStyle = .overFullScreen

            var rootViewController = UIApplication.shared.keyWindow?.rootViewController
            while let presentController = rootViewController?.presentedViewController {
                rootViewController = presentController
            }
            rootViewController?.present(passcodeManageView, animated: false, completion: nil)
    }

所以，我的问题是

1. 密码视图如何覆盖 MFMessageComposeViewController？

2. 或如何关闭 MFMessageComposeViewController？

最好的方法是什么？？？

Answer 1

您需要迭代您的应用程序呈现的 ViewController 和 一一关闭。

func applicationDidEnterBackground(_ application: UIApplication) {  
    if let rootViewController = UIApplication.shared.keyWindow?.rootViewController {
      var  presented = rootViewController.presentedViewController
      while presented != nil
      {
        if presented is MFMessageComposeViewController {
          rootViewController.dismiss(animated: false, completion: nil)
          break
        } else {
           presented = presented?.presentedViewController
        }
      }

    }

    guard let passcodeManageView = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "passcodeManageView") as? PasscodeManageViewController else { return }
    passcodeManageView.state = State.loginMode
    passcodeManageView.modalPresentationStyle = .overFullScreen

    var rootViewController = UIApplication.shared.keyWindow?.rootViewController
    while let presentController = rootViewController?.presentedViewController {
      rootViewController = presentController
    }
    rootViewController?.present(passcodeManageView, animated: false, completion: nil)

}