这是我的视图控制器代码：

import UIKit
import AVFoundation

class ViewController: UIViewController {

  override func viewDidLoad() {
    super.viewDidLoad()

    if AVCaptureDevice.authorizationStatus(forMediaType: AVMediaTypeVideo) == .notDetermined {
      AVCaptureDevice.requestAccess(forMediaType: AVMediaTypeVideo,completionHandler: { (granted: Bool) in
        if granted {
          print("granted")
        }
        else {
          print("not granted")
        }
      })
    }
  }
}

当我在我的设备上运行此应用程序时,应用程序在执行AVCapture.requestAccess行后崩溃(未执行完成处理程序且不会抛出异常).

控制台中唯一的事情是：

2016-07-15 14:55:44.621819 testpp[2261:912051] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
2016-07-15 14:55:44.626012 testpp[2261:912051] [MC] Reading from public effective user settings.
2016-07-15 14:55:59.284610 testpp[2261:912085] [access] <private>

难道我做错了什么？