SwiftyDropbox 下载进度

Question

我正在使用此代码下载一个文件，它工作正常。

// 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!)
    }
}

我的问题是如何获取下载进度以显示给用户？

Answer 1

改编自tutorial , 你可以在 download 方法上添加一个 progress 回调来获取进度信息:

// 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支持您应用中的进度 UI。