我刚刚开始使用MessageKit,并已将我的代码迅速更新到4.2,并一直在解决问题。但是,我正在使用Firebase聊天教程,并且遇到了示例代码中的问题,这些问题引发了在示例项目中不可见的错误。
无法转换类型“ _?”的值预期的参数类型“ URL?”
completion(meta?.downloadURL())
答案 0 :(得分:1)
假设您的问题可能是以下原因
storage.child(channelID).child(imageName).putData(data, metadata: metadata) { meta, error in
completion(meta?.downloadURL())
}
答案,快速4
storage.child(channelID).child(imageName).putData(data, metadata: metadata) { metaN, error in
// then we check if the metadata and path exist
// if the error was nil, we expect the metadata and path to exist
// therefore if not, we return an error
guard let metadata = metaN, let path = metadata.path else {
completion(nil)
return
}
// now we get the download url using the path
// and the basic reference object (without child paths)
self.getDownloadURL(from: path, completion: completion)
}
private func getDownloadURL(from path: String, completion:@escaping (URL?) -> Void) {
let firebaseStorageUrl = "gs://yourApp-Firebase-Storage.appspot.com"
let storageReference = Storage.storage().reference(forURL: firebaseStorageUrl)
storageReference.child(path).downloadURL { (url, error) in
completion(url)
}
}
请确保已在Firebase中启用存储,并检查控制台错误(如果失败)