我已经实现了带自定义单元格的tableView与约会进度栏进行跟踪。
如何观察或跟踪快捷功能上的进度条?实际上,我不知道如何保存进度数据以及如何显示进度数据?我有这样的函数层次结构。
所有功能都非常有效地完成,但是
downloadPDFTask
函数花费很少的时间来存储文件。下载PDF正在使用alamofire
,并且进度只想跟踪它。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)
}
}
}
}
最佳答案
添加属性观察器downloadProgress
var downloadProgress : Double = 0.0 {
didSet {
self.tableView.reloadRows(at: [IndexPath(item: yourRow, section: 0)], with: .none) // do whatever you want here
}
}
然后为其分配proges的值。每当进度值更改时,就会调用
didSet
。 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)
})