我的表格 View 中有许多发票文件列表以及每个单元格中的许多下载按钮。当我单击其中一个时，它将下载发票文件。但是，问题是服务器响应建议的文件名是我下载的每个文件都有“invoice.pdf”。所以，我需要在下载文件后保存到文档之前手动编辑文件名。那么，如何在成功下载后手动编辑文件名并将其保存在文档中作为临时 url，而不使用 Alamofire.Request.suggestedDownloadDestination。

这是我的下载功能。

func downloadInvoice(invoice: Invoice, completionHandler: (Double?, NSError?) -> Void) {

guard isInvoiceDownloaded(invoice) == false else {
  completionHandler(1.0, nil) // already have it
  return
}

let params = [
    "AccessToken" : “xadijdiwjad12121”]

// Can’t use the destination file anymore because my server only return one file name “invoice.pdf” no matter which file i gonna download
// So I have to manually edit my file name which i saved after it was downloaded.    
let destination = Alamofire.Request.suggestedDownloadDestination(directory: .DocumentDirectory, domain: .UserDomainMask)
// So I have to save file name like that ““2016_04_02_car_invoice_10021.pdf” [Date_car_invoice_timestamp(Long).pdf]
// Please look comment on tableView code

Alamofire.Manager.sharedInstance.session.configuration.HTTPAdditionalHeaders?.updateValue("application/pdf",forKey: "Content-Type")

Alamofire.download(.POST, invoice.url,parameters:params, destination: destination)
      .progress { bytesRead, totalBytesRead, totalBytesExpectedToRead in
        print(totalBytesRead)
        dispatch_async(dispatch_get_main_queue()) {
          let progress = Double(totalBytesRead) / Double(totalBytesExpectedToRead)
          completionHandler(progress, nil)
        }
      }
      .responseString { response in
        print(response.result.error)
        completionHandler(nil, response.result.error)
    }
  }

这里是表格 View ，它将检查下载的文件，当它点击时，显示在打开的功能中。

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if let invoice = dataController.invoices?[indexPath.row] {
  dataController.downloadInvoice(invoice) { progress, error in
    // TODO: handle error
    print(progress)
    print(error)
    if (progress < 1.0) {
      if let cell = self.tableView.cellForRowAtIndexPath(indexPath), invoiceCell = cell as? InvoiceCell, progressValue = progress {
        invoiceCell.progressBar.hidden = false
        invoiceCell.progressBar.progress = Float(progressValue)
        invoiceCell.setNeedsDisplay()
      }
    }
    if (progress == 1.0) {
    // Here where i gonna get the downloaded file name from my model.
        // invoice.filename = (Assume “2016_04_02_car_invoice_10021”)
        if let filename = invoice.filename{
            let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
            let docs = paths[0]
            let pathURL = NSURL(fileURLWithPath: docs, isDirectory: true)
            let fileURL = NSURL(fileURLWithPath: filename, isDirectory: false, relativeToURL: pathURL)

            self.docController = UIDocumentInteractionController(URL: fileURL)
            self.docController?.delegate = self
            if let cell = self.tableView.cellForRowAtIndexPath(indexPath) {
                self.docController?.presentOptionsMenuFromRect(cell.frame, inView: self.tableView, animated: true)
                if let invoiceCell = cell as? InvoiceCell {
                    invoiceCell.accessoryType = .Checkmark
                    invoiceCell.setNeedsDisplay()
                }
            }
        }
    }
  }
}
}

所以，我的问题很简单。我只是不想使用该代码

let destination = Alamofire.Request.suggestedDownloadDestination(directory: .DocumentDirectory, domain: .UserDomainMask)

因为它使用 response.suggestedfilename。我想在选定的表格 View 单元格数据上手动保存文件名。有什么帮助吗？请不要介意我在我的问题中发布了一些代码，因为我希望每个人都能清楚地看到它。

最佳答案

目标是 (NSURL, NSHTTPURLResponse) -> NSURL 类型。所以你可以做这样的事情

 Alamofire.download(.POST, invoice.url,parameters:params, destination: { (url, response) -> NSURL in

    let pathComponent = "yourfileName"

    let fileManager = NSFileManager.defaultManager()
    let directoryURL = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
    let fileUrl = directoryURL.URLByAppendingPathComponent(pathComponent)
    return fileUrl
    })
  .progress { bytesRead, totalBytesRead, totalBytesExpectedToRead in
    print(totalBytesRead)
    dispatch_async(dispatch_get_main_queue()) {
      let progress = Double(totalBytesRead) / Double(totalBytesExpectedToRead)
      completionHandler(progress, nil)
    }
    }
    .responseString { response in
      print(response.result.error)
      completionHandler(nil, response.result.error)
  }
}

swift 3.0

在 swift 3.0 中它是 DownloadFileDestination

 Alamofire.download(url, method: .get, to: { (url, response) -> (destinationURL: URL, options: DownloadRequest.DownloadOptions) in
  return (filePathURL, [.removePreviousFile, .createIntermediateDirectories])
})
 .downloadProgress(queue: utilityQueue) { progress in
    print("Download Progress: \(progress.fractionCompleted)")
}
.responseData { response in
    if let data = response.result.value {
        let image = UIImage(data: data)
    }
}

有关更多信息，请访问 Alamofire

关于swift - 设置 Alamofire 自定义目标文件名而不是使用 suggestedDownloadDestination，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36785555/