当我使用UIImagePickerControllerSourceType.camera时，以未捕获的异常终止

Question

@IBAction func onlytest(_ sender: Any) {

        let imagePickerController = UIImagePickerController()
        imagePickerController.delegate = self

        let actionSheet = UIAlertController(title: "Choose image source", message: nil, preferredStyle: UIAlertControllerStyle.actionSheet)

        actionSheet.addAction(UIAlertAction(title: "Camera roll", style: UIAlertActionStyle.default, handler: { ( alert: UIAlertAction!) -> Void in
            imagePickerController.sourceType = UIImagePickerControllerSourceType.photoLibrary
            self.present(imagePickerController, animated: true, completion: nil)
        } ))

        actionSheet.addAction(UIAlertAction(title: "Take Photo", style: UIAlertActionStyle.default, handler: { ( alert: UIAlertAction!) -> Void in
            imagePickerController.sourceType = UIImagePickerControllerSourceType.camera
            self.present(imagePickerController, animated: true, completion: nil)
        } ))

        actionSheet.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel, handler: nil))

        self.present(actionSheet, animated: true, completion: nil)



    }

当我点击拍照时，我收到以下错误：

  

libc ++ abi.dylib：以NSException类型的未捕获异常终止“使应用程序崩溃

然而，当我点击相机胶卷时，它可以正常工作。

连接没有错误。有没有人有想法？