NSString的！ $ T4与[NSObject：AnyObject]不同

Question

我已经被困在这个错误上差不多两个小时了，无法弄清楚出了什么问题。我已经搜索了，它似乎是一个选项问题？我已经尝试搞乱选项，看看这是否会有所帮助，但事实并非如此。我试着用力展开无济于事。

错误发生在：self.videoURL = info(UIImagePickerControllerMediaURL)

我还将videoURL定义为：var videoURL: NSURL

func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [NSObject : AnyObject]) {
   self.videoURL = info(UIImagePickerControllerMediaURL)
   picker.dismissViewControllerAnimated(false, completion: nil)
   var sub = ShareViewController()
   sub.fileUrl = self.videoURL
   self.presentViewController(sub, animated: true, completion: nil)
}