使用Alamofire 4.0下载文件（Swift 3）

Question

在旧版本的Alamofire中。这是我下载文件的方式

let destinationPath = Alamofire.Request.suggestedDownloadDestination(directory: .documentDirectory, domain: .userDomainMask); 

    Alamofire.download(.GET, urlString, destination: destinationPath) 
     .progress { bytesRead, totalBytesRead, totalBytesExpectedToRead in 
//    print(totalBytesRead) 
     } 
     .response { request, response, _, error in 

      let downloadedFilePath = destinationPath(URL(string: "")!, response!); 

      NSUserDefaultsHelper.saveURL(downloadedFilePath, key: urlString); 

      completion(downloadedFilePath, true); 
    } 

但是现在在新版本中，我的代码完全无法使用，并且在Alamofire库中没有类似的功能。

有什么想法吗？

Answer 1

我用这个语句：

let destination = DownloadRequest.suggestedDownloadDestination(for: .documentDirectory) 

Alamofire.download(
    url, 
    method: .get, 
    parameters: parameters, 
    encoding: JSONEncoding.default, 
    headers: nil, 
    to: destination).downloadProgress(closure: { (progress) in 
     //progress closure 
    }).response(completionHandler: { (DefaultDownloadResponse) in 
     //here you able to access the DefaultDownloadResponse 
     //result closure 
    }) 

更多细节Alamofire docs about Migration to 4.0阅读更多：

Answer 2

有几种增强功能Alamofire 4.第一个是目标闭合的可选性。现在，默认情况下，目标闭包为零，这意味着文件不会在文件系统上的任何位置移动，并返回临时URL。

这是默认执行： -

Alamofire.download(urlString).responseData { response in 
    print("Temporary URL: \(response.temporaryURL)") 
} 

这是我的代码来下载文件，Alamofire 4.0返回该文件的目标网址： -

let destination: DownloadRequest.DownloadFileDestination = { _, _ in 
     var documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0] 
     documentsURL.appendPathComponent("duck.png") 
     return (documentsURL, [.removePreviousFile]) 
    } 

    Alamofire.download(url, to: destination).responseData { response in 
    if let destinationUrl = response.destinationURL ? { 
     completionHandler(destinationUrl) 
    } 
} 

Answer 3

斯威夫特3 Alamofire（4.4.0 ）：

.plist添加键“App Transport Security Settings-> Allow Arbitrary Loads-> Yes”如果您复制并粘贴以下代码：

import Alamofire 

    let destination = DownloadRequest.suggestedDownloadDestination() 

    Alamofire.download("http://zmp3-mp3-lossless-te-zmp3-bdhcm-1.zadn.vn/151e407bb43f5d61042e/1223048424027738068?key=f-zMo3GZKlhVibnvGMsMuQ&expires=1495726053&filename=See%20You%20Again%20-%20Wiz%20Khalifa%20Charlie%20Puth%20(NhacPro.net).flac", to: destination).downloadProgress(queue: DispatchQueue.global(qos: .utility)) { (progress) in 
     print("Progress: \(progress.fractionCompleted)") 
    } .validate().responseData { (response) in 
     print(response.destinationURL!.lastPathComponent) 
    } 

Answer 4

下载与Alamofire 4.0雨燕4.x的

MP3文件，由于几乎所有的样本似乎是有关下载图像或JSON文件，我花了时间，找到合适的解决方案。
我会在这里分享，希望能帮助别人节省一些时间。

func startDownload(audioUrl:String) -> Void { 
    let fileUrl = self.getSaveFileUrl(fileName: audioUrl) 
    let destination: DownloadRequest.DownloadFileDestination = { _, _ in 
     return (fileUrl, [.removePreviousFile, .createIntermediateDirectories]) 
    } 

    Alamofire.download(audioUrl, to:destination) 
     .downloadProgress { (progress) in 
      self.progressLabel.text = (String)(progress.fractionCompleted) 
     } 
     .responseData { (data) in 
      self.progressLabel.text = "Completed!" 
    } 
} 

func getSaveFileUrl(fileName: String) -> URL { 
    let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0] 
    let nameUrl = URL(string: fileName) 
    let fileURL = documentsURL.appendingPathComponent((nameUrl?.lastPathComponent)!) 
    NSLog(fileURL.absoluteString) 
    return fileURL; 
}