如何知道该应用程序在iOS8中具有摄像头访问权限或不能以编程方式

AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
if(status == AVAuthorizationStatusAuthorized) {
  // authorized
} else if(status == AVAuthorizationStatusDenied){
  // denied
} else if(status == AVAuthorizationStatusReStricted){
  // reStricted
} else if(status == AVAuthorizationStatusnotDetermined){
  // not determined
  [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
    if(granted){
  NSLog(@"Granted access");
} else {
  NSLog(@"Not granted access");
}
  }];
}