ios - 快速观察或跟踪每个功能上的进度条

Question

我已经实现了带有自定义单元格的 tableView 用于约会，并带有进度条进行跟踪。
如何观察或跟踪 swift 函数的进度条？实际上我不知道如何保存进度数据以及如何显示它？我有这样的函数层次结构。

预约电话(日期)

预约详情()

公司详情()

unitData()

unitDataHistory()

unitDataImages()

下载PDFTask(pdfURL: String)

All functions very efficiently completed but downloadPDFTaskfunction takes little time for files. download PDF is using alamofire and have the progress only want to track it.

我如何跟踪进度条？

下载PDF任务代码:

@objc public func downloadFile(url:String, filetype: String, callback:@escaping (_ success:Bool, _ result:Any?)->(Bool)) -> Void {
var destination = DownloadRequest.suggestedDownloadDestination(for: .documentDirectory)
if filetype.elementsEqual(".pdf"){
            destination = { _, _ in
                let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
                let downloadFileName = url.filName()
                let fileURL = documentsURL.appendingPathComponent("\(downloadFileName).pdf")
                return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
            }
        } 

        self.request = Alamofire.download(
            url,
            method: .get,
            parameters: nil,
            encoding: JSONEncoding.default,
            headers: nil,
            to: destination).downloadProgress(closure: { (progress) in

                print(progress)
                print(progress.fractionCompleted)

            }).response(completionHandler: { (DefaultDownloadResponse) in
                callback(DefaultDownloadResponse.response?.statusCode == 200, DefaultDownloadResponse.destinationURL?.path)
           print(DefaultDownloadResponse)
                })
    }

更新代码和图片:

var downloadProgress : Double = 0.0 {
      didSet {
        for indexPath in self.tableView.indexPathsForVisibleRows ?? [] {
        if let cell = self.tableView.cellForRow(at: indexPath) as? DownloadEntryViewCell {
            cell.individualProgress.setProgress(Float(downloadProgress), animated: true) //= "\(downloadProgress)" // do whatever you want here
            print(downloadProgress)
            }
        }
      }
  }

Answer 1

添加属性观察者 downloadProgress

var downloadProgress : Double = 0.0 { 
    didSet { 
        self.tableView.reloadRows(at: [IndexPath(item: yourRow, section: 0)], with: .none) // do whatever you want here
    }
}

然后为它分配progress的值。 didSet每次进度值更改时都会调用。

    self.request = Alamofire.download(
        url,
        method: .get,
        parameters: nil,
        encoding: JSONEncoding.default,
        headers: nil,
        to: destination).downloadProgress(closure: { (progress) in

            print(progress)
            print(progress.fractionCompleted)
            self.downloadProgress = progress // assign the value here. didSet will be called everytime the progress value changes.
        }).response(completionHandler: { (DefaultDownloadResponse) in
            callback(DefaultDownloadResponse.response?.statusCode == 200, DefaultDownloadResponse.destinationURL?.path)
       print(DefaultDownloadResponse)
            })