Question

我使用此代码下载文件，但效果很好。

// Download a file

let destination : (NSURL, NSHTTPURLResponse) -> NSURL = { temporaryURL, response in
    let fileManager = NSFileManager.defaultManager()
    let directoryURL = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
    // generate a unique name for this file in case we've seen it before
    let UUID = NSUUID().UUIDString
    let pathComponent = "\(UUID)-\(response.suggestedFilename!)"
    return directoryURL.URLByAppendingPathComponent(pathComponent)
}

client.files.download(path: "/hello.txt", destination: destination).response { response, error in
    if let (metadata, url) = response {
        print("*** Download file ***")
        let data = NSData(contentsOfURL: url)
        print("Downloaded file name: \(metadata.name)")
        print("Downloaded file url: \(url)")
        print("Downloaded file data: \(data)")
    } else {
        print(error!)
    }
}

我的问题是如何向用户显示下载进度？

Answer 1

改编自tutorial，您可以在progress方法上添加download回调以获取进度信息：

// Download a file
let destination : (NSURL, NSHTTPURLResponse) -> NSURL = { temporaryURL, response in
    let fileManager = NSFileManager.defaultManager()
    let directoryURL = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
    // generate a unique name for this file in case we've seen it before
    let UUID = NSUUID().UUIDString
    let pathComponent = "\(UUID)-\(response.suggestedFilename!)"
    return directoryURL.URLByAppendingPathComponent(pathComponent)
}

Dropbox.authorizedClient!.files.download(path: "/path/to/Dropbox/file", destination: destination)

    .progress { bytesRead, totalBytesRead, totalBytesExpectedToRead in

        print("bytesRead: \(bytesRead)")
        print("totalBytesRead: \(totalBytesRead)")
        print("totalBytesExpectedToRead: \(totalBytesExpectedToRead)")

    }

    .response { response, error in

        if let (metadata, url) = response {
            print("*** Download file ***")
            print("Downloaded file name: \(metadata.name)")
            print("Downloaded file url: \(url)")
        } else {
            print(error!)
        }

    }

然后，您可以使用该原始进度信息来备份应用中的进度UI。

Answer 2

在Swift3上，Dropbox API V2已更新，.progress已更新为progressData为NSProgress。

Dropbox官方信息 its documentation

NSProgress Apple API参考 https://github.com/dropbox/SwiftyDropbox#upload-style-request

所以，Greg的Sample会像这样更新，

dropboxClient.files.files.download(path: "/path/to/Dropbox/file", destination: destination)

.progress { progressData in

    print("bytesRead = totalUnitCount: \(progressData.totalUnitCount)")
    print("totalBytesRead = completedUnitCount: \(progressData.completedUnitCount)")

    print("totalBytesExpectedToRead (Has to sub): \(progressData.totalUnitCount - progressData.completedUnitCount)")

    print("progressData.fractionCompleted (New)  = \(progressData.fractionCompleted)")

}

.response { response, error in

    if let (metadata, url) = response {
        print("*** Download file ***")
        print("Downloaded file name: \(metadata.name)")
        print("Downloaded file url: \(url)")
    } else {
        print(error!)
    }

}

Answer 3

在swift 3中，我们应该下载格式

let path = "/Files/\(textTitle).txt"


          _ =  client?.files.download(path: path).response{response,error in

                if let response = response{

                    let responseMetadata = response.0

                    let filecontents = response.1 . // File in encrypt format

                    let description = String(data: filecontents, encoding: String.Encoding.utf8)!   //Decrypting the file


                }else if let error = error{

                    print("The Download error is \(error)")
                }

希望它有所帮助。

SwiftyDropbox下载进度

3 个答案: