ios - UIApplicationOpenURLOptionsKey.sourceApplication 可以为零吗？

Question

最近在新的应用程序更新后，我们开始排队

let sourceApplication = options[UIApplicationOpenURLOptionsKey.sourceApplication] as! String

在下面的代码中。我只是想知道为什么它可以为零或者因为 as 而崩溃!串起来？

    func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey: Any] = [:]) -> Bool {
    CoreAnalytics.shared.record("AppDelegate", action: "Open URL")
    Branch.getInstance().handleDeepLink(url)
    let sourceApplication = options[UIApplicationOpenURLOptionsKey.sourceApplication] as! String
    let annotation = options[UIApplicationOpenURLOptionsKey.annotation]

    CleverTap.sharedInstance()?.handleOpen(url, sourceApplication: sourceApplication)

    return
        GIDSignIn.sharedInstance().handle(url, sourceApplication: sourceApplication, annotation: annotation) ||
        FBSDKApplicationDelegate.sharedInstance().application(app, open: url, sourceApplication: sourceApplication, annotation: annotation)
}

Answer 1

这是在从 Apple wallet pass 打开应用程序时发生的。