成功上传文件后，来自 Firebase 存储的 downloadURL 为零答案

【问题标题】：downloadURL from Firebase Storage is nil after successfully uploading a file成功上传文件后，来自 Firebase 存储的 downloadURL 为零
【发布时间】：2019-07-08 13:00:08
【问题描述】：

我是 firebase 新手，在这里遇到了问题。

我已经成功地将我的图片上传到了 firebase 存储，但是，我需要立即获取下载网址并将其发布到数据库中。而且我不确定为什么它在该闭包中不起作用。

以下是我的代码：-

   func CreateNewChatRoom(user: User, caption: String, data: Data){
    let filePath = "\(user.uid)/\(Int(NSDate.timeIntervalSinceReferenceDate)).jpg"
    let metaData = StorageMetadata()
    metaData.contentType = "image/jpg"
    let reference = storageRef.child(filePath)

    reference.putData(data, metadata: metaData) { (metadata, error) in
        if let error = error {
            print("\(error.localizedDescription)")
            return
        }
        reference.downloadURL(completion: { (url, error) in
            if let error = error{
                print("Error : \(error.localizedDescription)")
                return
            }
            else{
                if let downloadURL = url?.absoluteString {
                    let idRoom = self.BASE_REF.child("rooms").childByAutoId()
                    idRoom.setValue(["caption":caption, "thumbnailUrlFromStorage": self.storageRef.child(metadata!.path!).description,"fileUrl": downloadURL])
                }
            }
        })

    }

}

【问题讨论】：

那么你得到了什么结果？您的代码是否正确获取了网址？
我得到 fileUrl = nil，但我不确定它为什么不执行闭包块。我检查了我的 Firebase 存储，图片已上传。
我不断从 xcode 控制台收到此错误消息：BoringSSL] nw_protocol_boringssl_get_output_frames(1301) [C6.1:2][0x7fbcf8d25db0] get output frames failed, state 8196
如果你在 if let 的开头做了一个 print(downloadURL)，你看到 downloadURL 的值 do you have nil 吗？

标签： swift firebase firebase-realtime-database firebase-storage

【解决方案1】：

我有同样的问题，我找到了以下解决方案，我希望它对某人有用。斯威夫特 5

导入 FirebaseAuth 导入 Firebase 存储导入 FirebaseFirestore

typealias AddStoryResult = (Bool, Error?) -> Void typealias UploadImageResult = (StorageMetadata?, Error?) -> Void

类 StoryFirebaseAPI {

static let storage = Storage.storage()
static var downloadUrlString: URL?
var image: UIImage?

let photoUri = "smth uri path"

uploadImage(image, photoUriString: photoUri) { (metadata: StorageMetadata?, error: Error?) in
    
    guard let metadata = metadata else {
        if let error = error {
            print("Error occured: \(error)")
        }
        completion(false, error)
        return
    }

    // and at this point I have print(downloadUrlString)
    
    completion(true, nil)
}

}

扩展 StoryFirebaseAPI {

func uploadImage(_ image: UIImage, photoUriString: String, completion: @escaping UploadImageResult) {
    
    guard let imageData = image.jpegData(compressionQuality: 0.5) else {
        print("smth error")
        completion(nil, nil)
        return
    }
    
    let storageRef = storage.reference().child(photoUriString)
    
    let imageMetadata = StorageMetadata()
    imageMetadata.contentType = "image/jpeg"
    
    storageRef.putData(imageData, metadata: imageMetadata) { (storageMetadata, error) in
        
        if let error = error {
            print("Error: \(error.localizedDescription)")
            completion(nil, error)
            return
        }
        
        guard let unwrappedMetadata = storageMetadata else {
            print("smth error")
            print("Error: \(error?.localizedDescription ?? "")")
            completion(nil, error)
            return
        }
        
        
        storageRef.downloadURL { url, error in
            if let error = error {
                print("Error: \(error.localizedDescription)")
                completion(nil, error)
                return
            } else {
                if let url = url {
                    downloadUrlString = url
                    completion(unwrappedMetadata, nil)
                }
            }
        }
        print("Image uploaded successfully")
    }
}

}

【讨论】：