Swift 绝对字符串->&引用；类型为'的值；存储元数据&x27；没有成员'；下载URL'&引用；

刚刚更新了新的firebase，现在我在第10行得到了上面的错误。。。 它在firebase 3和4下工作，但当他们删除下载URL时，它在第五个版本中不再工作了。。。请不要重复这个问题或类似的问题，因为我已经在互联网上尝试了任何解决方案，但没有任何效果

fileprivate func handleVideoSelectedForUrl(_ url: URL) {
    let filename = UUID().uuidString + ".mov"
    let uploadTask = Storage.storage().reference().child("message_movies").child(filename).putFile(from: url, metadata: nil, completion: { (metadata, error) in

        if error != nil {
            print("Failed upload of video:", error!)
            return
        }

        if let videoUrl = metadata?.downloadURL()?.absoluteString {
            if let thumbnailImage = self.thumbnailImageForFileUrl(url) {
                self.uploadToFirebaseStorageUsingImage(thumbnailImage, completion: { (imageUrl) in
                    let properties: [String: AnyObject] = ["imageUrl": imageUrl as AnyObject, "imageWidth": thumbnailImage.size.width as AnyObject, "imageHeight": thumbnailImage.size.height as AnyObject, "videoUrl": videoUrl as AnyObject]
                    self.sendMessageWithProperties(properties)

                })
            }
        }
    })

---

//在putData response closer中，您可以获得带有以下更新代码的下载URL

metadata?.storageReference?.downloadURL(completion: { (url, error) in
              print(url)
            })

在此之前，你可以像这样退休

metadata?.downloadURL()

---

再加上一些解释