在ios中上传后如何从firebase获取缩略图？

Question

我正在快速将视频和图像上传到 Firebase。现在，当上传完成时，我正在获取图像 url。但网址是原始图片。我想在上传图像或视频时获得图像或视频的缩略图。我正在使用下面的代码。

let imagePath = withName

        let metadata = FIRStorageMetadata()
        metadata.contentType = mimeType
        metadata.customMetadata = ["index": String(describing: index), "contentType": mimeType]

        // Upload file and metadata to the object 'images/mountains.jpg'
        let uploadTask = storageRef.child(imagePath).put(data, metadata: metadata)

        // Listen for state changes, errors, and completion of the upload.
        uploadTask.observe(.resume) { snapshot in
            // Upload resumed, also fires when the upload starts
        }

        uploadTask.observe(.pause) { snapshot in
            // Upload paused
        }

        uploadTask.observe(.progress) { snapshot in
            // Upload reported progress
            let percentComplete =  Double((snapshot.progress?.completedUnitCount)!)/Double(snapshot.progress!.totalUnitCount)
            progress( String(format: "%.2f", percentComplete))
            print(percentComplete)
        }

        uploadTask.observe(.success) { snapshot in
            // Upload completed successfully
            //Download the the image from url and save it as Data in local directory
            print(snapshot.metadata?.downloadURL()?.absoluteString ?? "no url found......")
            completion(.success, (snapshot.metadata?.downloadURL()?.absoluteString), DIError.noResponse)

            // self.startDownloading(downloadUrl: (snapshot.metadata?.downloadURL()?.absoluteString)!, imageName: imagePath)
        }

Answer 1

我们有一个如何使用 Cloud Functions 和 Cloud Storage 生成缩略图的示例：https://github.com/firebase/functions-samples/tree/master/generate-thumbnail

缩略图会保存回 Cloud Storage，然后您可以下载适当大小的照片。