ios - 处理 IOS 设置更改的正确方法

Question

如果用户一开始不允许访问相册，我会弹出一个提示，有取消和设置可供选择。如果他选择设置，则会将他带到设置页面，他可以在其中为该应用启用相机和照片库。但是，一旦用户在设置中切换相机或照片库开关，我的应用程序就会崩溃，并打印输出“来自调试器的消息:由于信号 9 而终止”。下面是我的弹出代码

    @IBAction func cameraBarBtnPress(sender: AnyObject) {

    let photoAuthStatus = PHPhotoLibrary.authorizationStatus()

    switch photoAuthStatus {

    case .Authorized:
        presentFusumaCameraVC()

    case .Denied, .Restricted :

        showNeedPhotoAlbumAccessPopup()

    case .NotDetermined:
        PHPhotoLibrary.requestAuthorization({ (authStatus: PHAuthorizationStatus) in
            switch authStatus {
            case .Authorized:
                self.presentFusumaCameraVC()

            case .Denied, .Restricted :
                self.showNeedPhotoAlbumAccessPopup()

            case .NotDetermined:
                print("Shouldnt get to here")
            }
        })
    }
}

func showNeedPhotoAlbumAccessPopup() {
    let alertController = UIAlertController(title: "Enable Photo Album Access", message: "", preferredStyle: .Alert)
    let cancelAction = UIAlertAction(title: "Cancel", style: .Default, handler: nil)
    let settingsAction = UIAlertAction(title: "Settings", style: .Default, handler: { (action: UIAlertAction) in
        let settingsUrl = NSURL(string: UIApplicationOpenSettingsURLString)
        if let url = settingsUrl {
            UIApplication.sharedApplication().openURL(url)
        }
    })
    alertController.addAction(settingsAction)
    alertController.addAction(cancelAction)
    self.presentViewController(alertController, animated: true, completion: nil)
}

处理此问题的正确方法是什么，以便用户可以在切换开关后返回到应用并开始选择照片？

Answer 1

Apple's documentation说如下:

• If permissions changes, app is quit
• Background task expiration handler is called, if registered
• iOS then kills the application

到目前为止还没有找到解决办法。