Question

我的应用程序支持打开其他应用程序中的文档，例如图像，pdf。 Tocuh ID的实现如下所示，当应用程序进入前台时会被请求

NotificationCenter.default.addObserver(forName: .UIApplicationWillEnterForeground, object: nil, queue: .main) { (notification) in
        LAContext().evaluatePolicy( .deviceOwnerAuthenticationWithBiometrics, localizedReason: "Request Touch ID", reply: { [unowned self] (success, error) -> Void in
             if (success) {

             } else {

             }
})

现在，当用户从后台打开应用或重新启动应用程序时，请求触摸ID的工作正常。当从其他应用程序打开该应用程序时会出现问题，例如点击应用程序URL，使用“复制到MyApp”选项从外部应用程序共享文档，其中，AppDelegate的打开url方法的调用如下所示

public func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
    //validate and save url
    return true
}

问题是从外部应用程序启动应用程序时，将调用上述打开的url方法，并且还会按预期调用 UIApplicationWillEnterForeground 观察器。但是在该UIApplicationWillEnterForeground观察器中，LAContext（）。evaluatePolicy突然失败，并显示错误消息“呼叫者移至后台”。

请注意，该问题可以在iOS 11.0.3、11.3 上看到，而在iOS 11.4或<11

上无法再现

Answer 1

您需要在应用为applicationDidBecomeActive时添加此内容

NotificationCenter.default.addObserver(forName: .UIApplicationDidBecomeActive, object: nil, queue: .main) { (notification) in

let context = LAContext()

var error: NSError?

if context.canEvaluatePolicy(
    LAPolicy.deviceOwnerAuthenticationWithBiometrics,
    error: &error) {

    // Device can use biometric authentication
    context.evaluatePolicy(
        LAPolicy.deviceOwnerAuthenticationWithBiometrics,
        localizedReason: "Access requires authentication",
        reply: {(success, error) in
            DispatchQueue.main.async {

                if let err = error {

                    switch err._code {

                    case LAError.Code.systemCancel.rawValue:
                        self.notifyUser("Session cancelled",
                                        err: err.localizedDescription)

                    case LAError.Code.userCancel.rawValue:
                        self.notifyUser("Please try again",
                                        err: err.localizedDescription)

                    case LAError.Code.userFallback.rawValue:
                        self.notifyUser("Authentication",
                                        err: "Password option selected")
                        // Custom code to obtain password here

                    default:
                        self.notifyUser("Authentication failed",
                                        err: err.localizedDescription)
                    }

                } else {
                    self.notifyUser("Authentication Successful",
                                    err: "You now have full access")
                }
            }
    })

}

})

iOS：调用AppDelegate的打开URL时不显示触摸ID

1 个答案: